I remember hearing about this when it first happened, congratulations on being back out there Alex. I've never met you, but I have an idea of what it takes to keep fighting and get back a dream you didn't think you would be able to be a part of again. In November 2009, I was in the police academy and about halfway finished when I was shot outside of class right above my right elbow. The bullet totally shattered my humerus and left the upper and lower half of my arm held together only by muscles and skin. I had to have two titanium plates and 17 screws put in to hold the bone together and spent three days in Tampa General Hospital. I had to do 10 months of occupational therapy three times a week and have a second surgery in December 2010. Docs told me I'd never be able to do push-ups, lift weights, or go back to the academy. I was supposed to have 80% total use out of my arm (strength, range of motion, grip strength etc). I lost some range of motion due to the damage and the scar tissue but I have just as much strength in my right arm as I do my left and my hand is actually stronger than the left one. It took me 21 months to regain the strength and use I lost in my arm, but I did it and Monday will start the 12th week of the class I'm in now.
Your advice about embracing what you have because it may not be there tomorrow is 100% spot-on. I HATED doing push-ups during PT and class before I got shot, but laying in that hospital bed, that was all I wanted to be able to do again. Odd how stuff like that works.
I hope you're able to get back to playing like you did prior to your diagnosis and have no future health problems.