Sounds very familiar..
Hows your head/neck/shoulder posture? forward of body , hunched or rolled forward.. all those close down the chest where nerves & blood need to flow..

Choking & collar bone sensation = look for top rib mobilisations..
armpit pain - look for pec minor & lymph drainage massage

We have posts on those so our search can find those or web search , also videos on you tube cover it too.
https://www.neurotalk.org/search.php

Expert PT or expert chiropractic care and lots of self care & limiting activities that aggravate symptoms can help to reverse it.

Do you know what brought it on?
desk work/repetitive, injury?

Unless your dr is knowledgeable on repetitive motion/TOS type issues, you may not get clear diagnosis.. Some say they are, but some have a bias if testing or imaging doesn't show a clear cut cause..

Explore our sticky threads and use the search tool- lots of info has been covered over the years..
https://www.neurotalk.org/search.php