I wonder if it (whatever it is, carpel tunnel, tendonitis, or something else) could be related to doing a lot of sleeping/lying on your left side? I know I had some serious hip stuff going on a few weeks back (I had that massage on Father's Day and the pain had reached its peak just before that, so I guess back in June...) and it was the left hip.
The crippling hip stuff started up after I had begun lying down a lot more during the day (always on my left side) and just resting or napping much more often. I also felt a lot more pelvic pressure and the twins had dropped much lower (I was obviously carrying lower), so I figured maybe I just was having the typical "increased difficulty getting around" or whatever as my pregnancy progressed.
But after getting the massage, the issue was appreciably better (not gone, but MUCH improved) and I decided to start alternating sides. I spent some time on my right side when I'd rest, and in the night whenever I got up to pee, I'd switch sides. I haven't had that same type of stabbing pain since. (I have a hard time walking when I get up, and my hips hurt in the morning/at night when I get up to pee, but that is related to slipping off the pillows or just difficulty getting my legs under me....it does go away with a little motion. i.e., By the time I'm on my way back from the bathroom trip, I can walk.)
I know side sleeping can lead to shoulder/arm stuff for me, depending on how I'm lying and how my arm is fitting under/around the pillows at the top.
Anyway, maybe switching things up a bit could offer some relief, too? I hope you're doing okay.
Also--just an afterthought, but are you wearing any rings or a watch at this point? I had my wedding/engagement rings off in the 2nd trimester because I was playing some gigs and had to hold drumsticks, and the rings would click (I usually remove my rings for percussion gigs, depending on what I'm playing. This gig was lots of snare drum, so off they went!) I never put them back on. I figured I'll wear them again after I get home from the hospital, and I won't have to worry about remembering to leave them at home when we go to the hospital.
I haven't tended to swell, certainly not appreciably, but I notice sometimes my watch band is a little more snug than others. (Seems to relate to the heat more than anything else.) Anyway, maybe some relief could come in losing any of that stuff that you might still be wearing.