Have you had an expert PT evaluation?
The hand, arm, overhead /in front sounds very TOS like to me..
If you raise arms up high do they turn pale, and flush when lowered?

Our TOS forum has much more good info that will help you decide if TOS might fit..
Even if it doesn't it could be a pre TOS or RSI of some sort, so the info is very beneficial. Explore the sticky threads there.

Many with TOS are tilted - high shoulder on one side , uneven hips, knees etc...
Posture work, expert PT or chiro might be good..
Top rib mobilization might help if tension around collar bone and limited breathing.
Forward head/shoulders/ hunched etc?

Xray or MRI to check C spine & for extra cervical ribs...

NTOS is nerve related VTOS is blood flow related

Few MDs know all the facts of TOS or ignore until it is full blown, then you might need surgery or pain meds.
Seek a TOS knowledgeable MD, PT, DC..some say they know but only limited knowledge..
That's why we have the stickys so others learn and can find the best care providers....
Don't stay with any that ignore to your concerns..
If just a few symptoms fit take action to reverse before it is chronic..

https://www.neurotalk.org/thoracic-outlet-syndrome/
sticky threads are above the main posting section..


TOS testing positions - Google Search