A question:

"Why, why, why can't I seem to correct my self defeating ways...? I'm having serious trouble leading a healthy, proactive life for myself and the ones I love..."

Notice that this question supposes that you CAN'T correct self defeating way. This is a negative thought loop that can keep you from growing and may be the cause of a continuation of habitual self-defeating thinking.
When this thought comes up how about rephrasing a bit:

How can I correct my self defeating ways? I would like to lead a healthier and more productive life!

Now you CAN do it. Maybe you're not sure by exactly what method it will come about but letting the question be positively answerable is half of the way to not being self defeating.

Don't worry or beat yourself up about unhealthy habits. I would go and find some good new ones before getting all worked up about "quiting" things you know aren't serving you.
Get out in your community, volunteer or meditate. See what's out there...I know there is a lot out there...more and more

Mostly start with the thoughts. No more negative unanswerable questions that leave you stuck in the muck!

My brother Brownie, it is only illusion which keeps you from experiencing a new reality. Your concept of self will dictate what self becomes. You are God, as such, you are the creator of your own reality.
If you tell the universe you are a lazy, sloppy, unhealthy slob, you will become just that. If you tell the universe you are a God, all powerful, knowing and loving, you will become just that. Let me lay a couple of facts about who you really are.

1./ You were never born and will never die.
You are not your body. Think of your body as the little car you ride in when on a roller coaster. You are consciousness Brownie. Consciousness is not physical, it is energy. The consciousness you enjoy has been with you forever and will be with you for ever more. I am the same consciousness as you, we are not separate we are truly one. Every sentient being in the multiverse is the same consciousness as us, we are all one. Our name for consciousness is the same all around the world " I ". Consciousness is energy it can neither be created nor destroyed it is eternal.
2./ The world around you is not physical.
You may perceive the desk you sit at, the computer you type on and your own body to be physical or material things. This is an illusion, our world is made up of energy. The frequency at which energy vibrates is what creates the illusion of physical matter. Our world is best described as a quantum holograph.
3./ Dualism is an illusion. It is only your believe in good and bad which keeps you from loving yourself.
4./ You are God. Great spiritual masters and scientists around the world will teach you every atom in all of creation is interconnected. There is only energy. Everything, all expression, manifest and unmanifest is this energy. Some call it God some call it love, either way this is exactly what you are Brownie.

How does this apply to you Brownie?

If you can come to know these four truths mentioned above you will never ask that silly question you asked to commence your blog.

1./ When we see our life in the context of a given span of years we create angst. We feel we have to measure up to others, which usually means having more than others. If you knew your life to be eternal Brownie, you would not feel so compelled to stuff yourself with today.
2./ You see the world as real, it is most certainly not. This lifetime you are experiencing Brownie is better described as an amusement park ride. The holo-deck on star treck is a much more realistic depiction of true reality than you would ever believe. Your body is the seat which affords the experience of the ride, your consciousness is the one riding not the body.
3./ Because you cannot yet understand there is only one, you cannot understand there is only love. Imagine if you loved everything and everyone Brownie. Don't you think your life would change? When you learn that all mass is energy and all energy is love then it impossible to not love everything. Breaking the bonds of fear and hate are crucial in understanding your every expression is love. It is only your false perception of reality which allows pain in your heart Brownie.
4./ When you know yourself as God you will become one with the world. Pain will be replaced with love, you will never look back.

Your messy behaviour is contributing to your inability to see clearly. Clean your home; taking pride in your environment will lead to taking pride in your reflection.
Your body is your temple. How can your mind function properly if you destroy your body. Respect in your body will come as you begin to realise who you really are Brownie.
Exercise your body and mind. Sell your television, instead use the time for reading and physical activity. If you can go without T.V. for a month you will never go back.
Empower yourself, stop crying pathetically about what is wrong. You are God, start acting like it.

Solution; If you are just blathering for attention, then I have obviously been wasting my time. If you are sincere Brownie, then I am prepared to work with you privately by e-mail. If you give me three months of your confidence and attention your life will change forever. When we are done Brownie, I promise, you will never give your power away again.

Namaste, my brother Brownie, I love you. Soar like the eagle into the light.

Hello Fellow Traveler,
You are being tossed about by the stream of thoughts that are being generated by conflicting subconscious programs, and fundamental confusion as to who YOU are. The Lower Self only identifies with the embodied personality and the embodiment experience, which is just a very small part, a sliver of the real, Higher Self-enSouled Spirit which is the authentic YOU. Dual belief systems, especially when they are not in alignment,place you in a no-win situation of constant suffering. If you read The Voice of Knowledge by Don Miguel Ruiz, who also wrote the Four Agreements, you will recognize your predicament and have a strategy for changing the unworkable, faulty subconscious beliefs that are running your life through these negative, self-denying, self-sabotaging, self-destructive thoughts. I too, am a practicing spiritual healer combining spiritual healing, vibrational medicine, hypnosis, nutrition and intuitive work. You can visit my blog if you'd like to find out how the process of self-transformation works; www.ajnira.com but starting with The Voice of Knowledge and some of the great comments posted here, you are on your way.

Blessings,
Ajnira

Okay, firstly, I want to say how great it is to be in a community with people who offer such wonderful support to each other. I also think that some of the things that people have said are wonderful and should all be taken into account.
For myself, very recently I learned the importance of the material and the carnal. I have always been very spiritually and intellectually minded, sometimes maybe a little too much. I have found it has caused a negative feeling in me for the times when the baser instincts kick in (ie:laziness, frustration, anger, lust, etc) Lately I have been learning to give these things their place, and not to neglect the energy in the lower chakras. By doing so, not only have I found more enjoyment in the simple things in life (always a plus) but also that my own magic (energy) has increased in purity and effectuality. Harmony and balance must be achieved in all things. You are a spiritual being in a body and that body has needs, don't deny them completely or it will become an enemy that you cannot defeat.
You need to find the balance for yourself. One way is to allocate time for various activities, yes, even a time to be completely lazy. If you have trouble sticking to a schedule or getting yourself off the couch when it's time to do something, ask a friend to call you at certain times to make sure you're sticking to what you set out to do. When it comes to diet, I find that if unhealthy food isn't in the house, I usually won't eat it, and if the craving is strong enough to make me go out for it, then my body probably needed a little junk, which, in moderation, isn't bad for you.
I hope I was able to offer some practical advice. I'll admit, I need help with this myself sometimes...then again we all do...we're all human.