Susan, I deal with chronic back pain that often prohibits me from playing/practicing so I appreciate what you're going through. I hope your doc has some good suggestions.
I like your idea to study theory during your down time. I have this and recommend it:
Edly's Music Theory for Practical People. = https://www.edly.com/mtfpp.html
[u]Guitars:[/u] 2014 PRS Santana, 2013 PRS Paul's, 2009 PRS Hollowbody, 1972 Gibson ES-325, 2012 Fender Strat American Standard, 2012 Yamaha Pacifica, Martin M-36, Martin 000-15M, Seagull S6 Classic[br][u]Amps:[/u] Fender Blues Junior III, Boss Eband JS-10, Line 6 POD 500X, Quilter Microblock 45