Overtraining, Shoulders, Rehab
A cautionary tale for the lot of you.
In my youth I trained hard six hours a day, six days a week, and was never seriously injured by my workouts and practice. I loved sport fighting, and I got to be pretty good at it, but at the time there was no professional path for san shou/san da, and I had some very good scholarship opportunities, so off I went to university, where my training slacked off, little by little, until my career picked up and -- by my late-20s -- pushed my martial arts training aside entirely. I continued to stay fit with cycling, rock climbing, some parkour and general gymrattery, but lost ground on strength and general fitness.
At 34, with my career in a happy place and plenty of free time on my hands, I decided to get back into combat sports as a hobby (knowing full well I was too old to have a run at pro fighting), so I went to the gym and started training more or less as I had done as a boy, but a bit less because of work and so on. You can probably see where this is going, as I should have, but like most people I just hadn't properly anticipated the effects of the r34l aging.
I got back up to 4 hours/day of training, including power yoga every morning, working the gymnastics rings, doing 800 pushups and 200 pull-ups a day, lifting aggressively four times a week, and so on. Within six months I'd gotten myself back into decent shape... and trashed both my rotator cuffs and developed severe bicipital tendonitis on the right side. (If you're not sure what this means: I can't pull a t-shirt over my head without my girlfriend's help, and on bad days I can't lift a glass of water to my mouth with my right hand).
Now I'm benched for a month of rehab exercises, during which no weight may be placed on the shoulder, no rolling at BJJ, no punching, no yoga, no nothing, just legs and abs and disappointment, after which they'll decide whether I need steroid injections directly into my shoulders, and maybe surgery.
The ways to avoid this kind of thing include: not training too much in any one motion (800 is too many pushups, no matter what Kimura says), avoiding high reps/extremely heavy weights during overhead exercises, and working rotator cuff rehab exercises as prehab, preferably at the beginning of your workouts. If you don't know how to train your RC, find a trainer to run through the stretch/lift cycle with you -- you need your shoulders to be healthy to do much of anything. This advice goes triple for anyone 30+ years old.
Train hard, but be careful.
I second that having good rotator cuff strength is extremely important. I wrenched my rotator cuff really bad in high school during ROTC training and throwing blocks during football were hell. It wasn't until I started training in Muay Thai that I began strengthening my rotator cuffs and now I rarely have a problem with my shoulders. I just need to keep strengthening them to make sure they don't get weak on me.
Sucks that you've got to wait it out, jack, but give it some rest and you'll be 100%, just don't go off and start doing 800 pushups and stuff like that, or you'll wreck your shoulders again.