So glad you're on the mend. Hate when that stuff happens. It's so easy to just grab something not thinking, and 'yonk', your out of wack. Nice you can yoga and stretch yourself back to daily life. I know just sitting in this goofy chair in front of the computer for too long can cause pain in the hips and back. I use a timer to tell me "hey dummy, get up. Quit sitting for hours at a time." Protect thyself from thyselves habits of the absurd.
Hope you can one day get a liftable amp, or stick to that harmonica, I read about those somewhere down below.
I just spent the weekend lifting and hauling the old amp again, but I was sloooow. I've been doing the yoga twists regularly, it will probably become a daily thing as a preventative. Like a chiropractor will hold down one shoulder, then turn that raised knee gently the opposite way over the other leg, I was taught a way to do that to my own back. I call it the 'twist and shout', but it's not to be confused with the dance or anything fun or enjoyable of the same name.