Wow this sucks!!! Let's see I have been in that vicious circle physical activity helps but treatment not allowing it. I am hard on myself right now too. It is frustrating to want to or have been able to in the past do things and now can't it's more than grrrrrrrrrrrrrrrrr....I live with someone who is depressed and have been afflicted with depression for almost 20 yrs now. I has taken me a long time to "deal" with it. Like talking to your mother who is depressed she loves you means well and wants to help but it is difficult for you I understand that concept. For many many years it took all I had just to get up in the morning and it is still a fight now and again. You cannot compare diseases but depression can be just a big a monster as others. They are all demonds. Depression like others can be beaten too!!! Yes it takes the right combination and support you just gotta keep trying. It is that magic potion what works for you. May not work for someone else. You need to focus on the "quality of life". A good friend reminded me of that in a note I read today and she is right we need to live for today and well now I am just sounding like a preacher lol but when it comes to some of these situations repitition of the positive can help! Keep after those professionals and if the one isn't working push to get another...Demand help...that is far too long to be without help when you are in your situation.
About loosing muscle mass I understand that one they keep telling me to walk that is really hard and physio I don't think I am doing anything am used to gym workouts but it is just remember baby steps start small and rebuilt we have to rebuild from ground level. Just gotta think like that train cept change it "I know I can" the mind is a powerful ally or foe you have to choose what side you want it on!! Please take care and keep reaching out you will find the combination and it will work... I know this sounds like fluff but it isn't I am a surviver of depression, many chronic pain issues and now cancer. You deserve a full and happy life and you can have it with baby steps...It never seems that you have made it very far but when you look back man what a distance you have travelled..

Have you tried journalling? It really helps...keeps organized too I know when that my brain is mush sometimes and writing things down helps..