My hypothyroidism caused severe PN for years.
When I was pregnant it was the worst is ever had been.

Don't underestimate what hypo can do. When it is going on the body gets deposits of mucin around ligaments and edema results as well. The mucin doesn't go away, at least it didn't for me.

I'd consider your birth control pills, as a potential problem too.
Do you absolutely have to take them? Hormones (like during my pregnancy) also cause edema in the tissues.
This varies from person to person.

My carpal tunnel ran up my arm too when it was at its worst.
I'd wake up during the night feeling like my whole arm was on fire. 3 days after delivery, most of it resolved, as the physiatrist predicted.

It is difficult to find anything about mucin that is "useful" on the net. I just tried again, and found next to nothing. I don't think it has been researched much. One article said it "may" resolve YEARS after treatment to normalize thyroid function.
Therefore I don't expect doctors to know much about it either.
You can try searching as well. If you find anything useful, please link it here.

I know it took a full year for my feet to improve after I started levothyroxine. I did not get 100% back but a good 85-90% which is liveable. I did not use ANY HORMONES for menopause as a result. My hands still flare up enough to require my wrist splint braces now and then, usually when I overdo gardening/digging or carrying very heavy things like boulders etc. Hand sewing is also off the table. I can do needlwork for about 15minutes, tops!