I’m sorry to hear how advanced this has become. I wish you the best possible future. While I also have had difficulty maintaining body weight, I’m nowhere near in your situation and would not put out there that I can relate to your situation.

My situation was more sarcopenia and while quite thin and not super strong, I have pushed back from my lowest weight and being in a wheelchair unable to stand or walk, to graduating to a walker, and now pretty much walking on my own, but slowly. That was all accomplished though a PEG tube diet of my own creation in a blender, and several times a week physical therapy to build back some lean body mass. I wouldn’t say that things are normal, but they are manageable where I am. However progress plateaued a few months ago though I continue to try and pushback against all this. It takes a lot of effort and time. But I need to at least maintain the place that I have fought to get to.

Wish you better answers in the future. I’m going to reach out to some researchers I know in allied areas. If they say anything fruitful I will post it here. I wish I had something more insightful to contribute, and absent that something better stated for my desires to see you improve. I hope that your ability to manage the emotional aspects of this situation stay strong.
Brian