I too have been fighting with the disability system for 5 years now. It is a frustrating and unfair system from what I have seen when it comes to mental illness. Unfortunately if the disability can not been seen, such as an arm or leg missing, they do not want to believe one is disabled. They do not have a clue how debilitating mental illness can be.
I do have to say that drinking is not going to solve the problem. If the system states that your mental health issues are the result of drug/alcohol problems then the best thing you can do is put as much distance between the alcohol/drugs as you can. That means staying sober and clean. Also talk to another attorney. Don't give up fighting. Insist that the system do a mental health exam on you. I know it is frustrating and discouraging but one is only beat when one gives up. Keep getting back up and moving forward.
Take care and I do hope things improve for you soon.