The difference between ham hock and her mother who both have their own personal demons with addiction is that while someone can be addicted to food - food doesn't innately change who you are mentally. It distracts you from whats going on but it lacks the chemicals that do things like make you a completely different person (IE a shitty mother). Drug users at least have the excuse that, while under the influence, they generally have little to no control over anything other than their next fix. AL is addicted to food, and while she might get a little bit hangry when she's been forced to go more than 3 hours between her meals of 5 egg rolls... her food addiction is no excuse for the over all shitty and manipulative person that she is. Ignoring her user ways, she is uneducated and unwilling to admit that she is as naive as a 10 year old child. Bottom line AL: the reason your family has cut ties with you is because you refuse to take control of your life and continue to be the victim. Your mother, while it may be new, has at least shown that she is now willing to do better in life.
Is it so shocking that someone who is tiptoeing through the rocky stages of recovery might want to keep someone as negative as you out of their life? I need to say this again AL, YOU CONTINUE TO BE THE VICTUM. In every day situations and overall in life. The thing about being an adult is realizing that at some point you either let the cards that were given to you in life control who you are, or you overcome them. This goes beyond your food addiction, but is also a large factor there too. Being 500lbs is not the only aspect of your life that you need to get under control. We've all had shitty things done to us in the past (I would assume your mother included given her choices in life) and you don't see the mass majority of us eating ourself to death.
Just as important as getting healthy, you need to mentally get your shit together. When mental trauma occurs in children/teens lives it ultimately stunts their mental growth. It is clear that whenever you were taken away from your parents, this combined with whatever abuse might have happened whilst in foster care, has caused you to be forever stuck in that mental age. You are defensive to the point of stupidity, lack the ability to speak as an adult, use excuses even when they are bold faced lies at all cost to avoid admitting when you are wrong. You are quick to attach yourself to anyone who gives you the smallest amount of attention and are unable to keep long term friends because of petty in fighting that occurs in social groups of children age 10-17. Bottom line is until you get yourself to a therapist and sort out all that shit in your head, stop making excuses, and stop being a pathological liar there is NO reason for any of your family members to go out of their way to be in your life.