Ugh, I'm so sorry, that is miserable. I had it terribly the last two months with DS #1. I feel like I'm developing it again, but so far it is not nearly as severe.
As everyone has said, the braces definitely help. Also, even though this is an absolutely temporary fix, one of the best pain relievers for me was to hold my wrists under warm running water. I guess it was the combination of warmth and pressure, but it helped every time (for a while.)
Also, I've tried icing (logically, this should work as it shrinks swelling...) but I never really got relief from that. I read a few different articles about heating pads helping (logically they should NOT help, as heat induces swelling...) because the school of thought says that the heat loosens up the muscles surrounding the nerves that cause the pain. Surprisingly, this actually helped, and didn't seem to have any bad effects later brought on by increased swelling.
I also slept every night with my arms each propped up on stacks of pillows (yes, I kicked DH out of bed to do this lol.)
I hope you get some relief!! It is truly miserable. : ( But, on the bright side, it disappeared literally the day my son was delivered. : ) So there is an end in sight!