I registered just to ask the same thing this threads original poster said since I've got the exact same symptoms,
except my pain has been there for quite a while now and I can't seem to get rid of it.
But first, a little bit of background:
Guess I have to mention that I'm a bit overweight, weighing 230 lbs at 5,9 feet.
I started playing discgolf actively back in 2012, and around July I picked up sidearm throw and basically threw nothing else ever since.
Some time in the end of last summer I had some horrible wrist pain on my hand which healed after a couple weeks of break and everything was fine.
Then, this season around May I threw a couple of real hard sidearm throws with a cold shoulder and not nearly enough stretching or anything and I pretty much broke the shoulder.
The pain was so great I could not play for a week, and the fool that I am decided to repeat this same mistake twice after that.
Now, I can't throw sidearms much at all, no more than two throws a round maximum. (And even then, 200 feet maximum)
My sidearm used to be in great shape last summer, I could throw 280 feet with ease and great accuracy, and all kinds of shots too like hyzers, anhyzers, turnover shots and flex shots.
Now I throw backhand around 320-330 feet and I usually go around the local 12-basket course from two to three times a day and just feel tired in the end of it.
I'm pretty happy with my accuracy but obviously I still have a long way to go, big distances to gain.
Backhand doesn't hurt at all, even if I go all out and throw the disc with the rage of a thousand suns, no problem.
Oh, and I've tried everything I can think of to fix this, such as taking a week's break, using sports drinks after practice to cool off,
using cold gel or icebags to cool the shoulder after practice when I'm in pain, stretching alot before practice and simply not using sidearm for quite a while.
I think I've forgotten my beautiful sidearm-technique from last summer, now when I try to throw any faster all discs,
even overstable ones tend to flip over to the left and end up as a roller, what's up with that? I haven't the faintest clue.
I'll try to apply the pointers Flick4D made a couple of posts above to my technique and see if I can get rid of my shoulder-ache.
Any further information regarding these kind of issues would be appreciated, I don't know all too much about sports injuries and this site seemed to be like a good place to ask.