I wish that I had more advice, but here goes..... (esp. since I don't know how WC works in TN)
I would try to get a referral to a neurologist, who will probably do some tests that may or may not show anything. Tam (tshadow) has posted a list of these in the past...I'll try and find them for you.

If the neurologist doesn't help enough, I would try to get a referral to a pain mgmt doctor. I'm a big proponent of them because I happen to have found one who a). cares, and b). knows what he's doing.

Different things aggrivate different people. Typing too much seems to be universal. I can't/shouldn't lift anything over shoulder height or at arms-lenght from my body. Lifting even 1/2 gallon of milk with my left hand is baaaaaaad. Sleeping on the bad side can make it worse. Weather changes and cold weather can make pain worse.

Finally, I"m sorry about the cortisone shots! I had one in my other (right) shoulder about 6-8 weeks ago, and it hurt like all hell. It took a medrol dose pack and about 6 days for the pain to subside.

I also am in TN, and would be glad to give you any help I can. Send me a PM if you have any specific questions.