Have the drs clarified what type of TOS you have?
Nerve, Vascular ( artery or vein?) , pec minor also? or disputed TOS which is a mix or a sort of chronic RSI version?
You don't mention swelling or heaviness, and do mention pain , so I'm guessing probably mostly Nerve..
Drs & pTs -
http://neurotalk.psychcentral.com/thread135.html
Or post your location for suggestions of nearby TOS docs.
very useful mega crash course info -
http://neurotalk.psychcentral.com/thread84.html
I think most of us will suggest , if PT or anything aggravates your pain/symptoms , don't do it .. it only makes the nerves angrier. General PT will often use a standard generic plan and it rarely works out well for TOS.
If you can find a highly skilled and knowledgeable chiropractor , they may be able to be of help. Especially if they use a variety of modalities, for healing.
If there are misalignments at least those will be addressed so they won't impede progress.