I feel for you, and what you describe is exactly what I have experienced. My heart goes out to you - I remember so well what that is like.
The volunteering helped me so much. I was petrified the first time I went. I was fine. The more you get out, the more you realize that other people have fears, worries, concerns. When I was at home a lot I felt everyone else had it together, except me (which of course is rubbish). Someone here has as their signature "Be kind, as everyone is fighting some kind of a battle".
Support groups and hospital program were enormously therapeutic. Just listening to other peoples' stories.
The mother of Isaiah Thomas used to say,
"You take one step and the Lord takes two.
He'll work the wonder for you".
Thinking of you and wishing you well.