Justme8, your post really broke my heart. Yes, I have had some judgement - mostly by my mother and she wasn't nearly as overt as your family and friends.
I do agree with the advice to not say anything. These are people who IMO probably don't want to hear what you have to say. Their loss!
First, I will tell you that they have ZERO to be embarrassed about. Not now at your current weight or any other weight you may end up at. And if they don't want to be in your life as it is right now, they don't deserve to be in it when you are what they deem to be a more "acceptable" weight.
IMO you don't need to snub them...you can be cordial but don't go out of your way to spend time with them. I realize we're talking about your father here and I'm sorry for that. Hopefully at some point he will find the same strength your finding with your weightloss journey and leave his fog of alcohol. Hopefully then, he'll see what a special kid he has.
In the meantime, nurture those friendships and relationships that nurture YOU. Take care of you