I stumbled here from all and I want to be clear that I'm not wheelchair-bound. But your concern about your weight doesn't make you weak or shallow; it only means you're human.
I had a professor drill into my brain: "You can't have personal growth without struggle, without hardship."
What makes us a strong person in a human sense isn't physical strength; it is tenacity and preservence.
It sounds to me like you've had an immense struggle you're going thru, but you're preserving. I don't want to come in here and sound like I'm telling you how to feel. But I don't read your post as written by a weak individual.
I read it as someone who is strong-willed and fighting to cope with life's bullshit. Someone who will be stronger as you face this struggle.
I hope you give yourself credit for what you've gone thru and already adapted to/learned to cope with.