@vincitygialam,
Get counseling. Get some tools for shoring up your self-esteem, and for dealing with your drinking. Drinking to blackout status is a sign of a deep problem. Yes, even if it only happened that one time.
Take care of yourself for a while and heal. You're not done yet.
Feel free to reach out to him during the holidays but
ONLY to tell him Happy Holidays (or Merry Christmas, Happy Chanukah, or Joyous Kwaanzaa, etc. as appropriate) and
NOTHING ELSE.
Then step back and continue to work on yourself, and that also means your physical health. Eat better, exercise, drink water, avoid too much salt, and get enough sleep. All of those things will make you feel better physically and they may be enough to get you to lose the weight without anymore effort or with not too much more effort. Don't get hung up on numbers on a scale (and I'm not suggesting adding a few pounds means you're not lovable. Of course you are, at any size!). Better self-care habits will stand you in good stead for all sorts of other reasons that have nothing to do with scales or lost relationships.
Also? See your friends. Go out in the world and meet people. Take a class or go to Meetup and get together with cosplayers or knitters or people who play World of Warcraft or whatever floats your boat. Get outside more, even when the weather stinks.
All of these things will help you feel better but they are not a substitute for counseling, which I still think would be a damned fine idea.
Take care of yourself. You may find your dream changes, and someone else fits it. Or that this guy comes back in time. Or you do something else.
But hanging around and wallowing in these bad feelings, checking off dates on a calendar (even if purely figuratively), is really not the way to go.
There's only one you. You're worthwhile with or without this guy.
Don't put your life on hold for him or anyone else.