Hey man, that could be me your describing, or for that matter any number of people your describing, and not just on this forum.You are suffering from deppression. Its my guess your self medicating with alcohol, and to a lesser extent food, as you are already aware this isnt working, and it cant work. Put simply you have an imbalance with the chemicals(NURO TRANSMITERS) in your brain, and no amount of food and alcohol, can alter that fact, you can mask it to an extent, with booze, but you need to restore that imbalance,as i mentoined above.
Im not a GP but I suffer from deppression, and have done masses of research.I have been trapped in the vicious cycle you have described above, My suggestion to you is you probably need an SSRI, type drug to elevate your levels of seretonin,(the feel good drug) in your brain.Though you should see your GP, about this, Fluoxitine also known as PROZAC.
Another big help, will be adopting a healthier lifestyle, bin the junk food, try to reduce your alcohol consumption, and start EXERCISING, loosing a little bit of beef, and regaining control of your eating habbits, will boost your self esteem.
Take steps now, the longer you leave it the more you will suffer, If I can be of any further help dont hesitate to get in touch,All the best.