As I was reading your post I thought you were going to go on to say, if you feel like isolating, don't!
If you know you have mental health issues and you feel the need to isolate (when you are not a threat to anyone else), please don't. Please see your GP, please ask them for help. If you are not receiving the help you need there, find another GP or call your local or national mental health department for a referral to services.
It is easy for me to say, I know, much harder to do, but isolation when you need help is never helpful, in my opinion.
If you are feeling isolated and feel the need to drink, perhaps a fellowship like AA would be helpful?