I had literally the exact same experience as your first two paragraphs. Where my experience diverged is when I met a doctor of some kind who explained that it's the same kind of pain that truckers often get for resting their arms on the armrests. Turns out it was because I was resting my arms on the keyboard or the desk between me and the keyboard. Stopped doing that, the pain went away completely within a few days, and hasn't come back since. That was like 4 years ago. Just don't rest your arms on anything, that's the trick.