Would it help if I said I know exactly how you felt about drinking? There were points in my younger days when... Well, I won't say I was an alcoholic, but when I did drink, I drank to get drunk as quickly as possible. These days, I allow myself a beer or hard cider once every other month at best. Maybe mead if it's a special occasion. And the hard stuff is right out.

If I may... try going back to basics. Schedule some time (if possible, I know) to go for a walk by yourself. Someplace safe but where there's not too many people: park, cemetery, botanical gardens. Take your sketch pad and doodle; don't try to draw anything, just let the pencil skip over the page. Don't even look at the paper. Or pick something innocuous and draw that instead. I remember trees being my favorite subject, all dark and light and angles against the sun; an art teacher once told me that sometimes the best way to draw something was not to sketch it in lines but to draw the shadows instead. i know you generally prefer to draw characters, but perhaps a change of pace might help?

In the meantime, be assured of one thing. I may not have clawed my way back into the light either, but I'll help you climb as best as I can.