Very common. I know many people with the same story. You just shifted addictions. I am an AA'er and what I believe, is that addiction is addiction - whether you eat it, drink it, screw it, snort it, shoot it etc. We use substances to get out of ourselves and our feelings and to deal with/cope with life. You switched from food to booze. I suggest a 12 step meeting, centered around the big book of AA, to help you.