longevity in guitar playing

So I was a music major. I used to play for hours upon hours a day. Then after college, I started getting aches in my joints.

Then i severed some of my fingers off in a table saw.

I didn't play for 5 months or so, and currently can only play for 5 - 10 minutes before I'm in pain.

I don't really remember any of my pieces or songs, i remember scales but the fingering is obviously completely different, and I just don't know if I should keep playing or try to keep going.

I think because I used to know very complex things, and because i lost a lot of strength, that now i push down too hard and it's hard on my joints.

any ideas to help me out so i don't tire?

perhaps i should just do easy single note exercises or scales. i play/ed a lot of chordish/folk/classical.

ps: fml