You need to attend a dual recovery group for a person with a psychiatric disability and alcohol/substance abuse issue. That is part of the key to gaining control over this. You may very well have bipolar as self medication can be a part of it but medication can't work as it should when a person is drinking at that level so that needs to be dealt with as well. You should speak to a psychiatriast about all this and see if they can give further advice and referrals for any other coping issues and what to do from there.
For starters you need to stop drinking any time you use anything mind altering it can cause depression, bipoler etc. While your under the influence. If you can't quit go to treatment. Talk to a counselor. Your behavior while drunk could be your drinking to much or the alcohol helps you to do what you want to do sober but can't while your sober.