Some of your symptoms sound like they could be coming from thoracic outlet syndrome (TOS), which would mean there is nerve compression in the brachial plexus and/or your eighth cervical or first thoracic nerve, and/or vascular compression in your subclavian blood vessels. A lot of weightlifters have this problem, which is part of the reason your post caught my eye.
TOS can be very difficult to diagnose. Many doctors are unfamiliar with it, some do not "believe" in it, and there is no one scientific test to rule it in or out, usually. Your best bet would be to consult a top TOS specialist like Dr. Donahue at Mass General in Boston. If you go to the TOS forum and check out the Drs. and PTs listed in the sticky thread at the top - or do a forum search, for more current info - you will find other TOS docs who may be closer to you. (Sorry, I'd post the link up here for you if I knew how to do that… but I'm pretty remedial when it comes to computer stuff!

)
There's a ton of info and links to medical literature on TOS, useful therapy modalities, etc. captured in the other sticky threads, if you want to do a little research

- or just browse the threads in the TOS forum for a bit, see if anything resonates with you.
Hope you find the answers you are looking for and are on the mend soon!
Alison