Some things that may help a bit (they helped me)
- "Healthy Hands, Wrists and Forearms" DVD by Martin Gray. You may have to hunt fairly hard to find it, as it seems out of stock in a lot of places. Shows about 20-25 minutes of stretching exercises that are pretty easy to do, and really make a difference if you do them REGULARLY.
- Microsoft "Natural" keyboard - that's the one with the 2 banks of keys and the split in the middle. Gives your wrist a more normal angle
- Wrist rests (I gave up on them when I bought the keyboard I mentioned above, but used to use them)
- Decent supportive chair. I have a Herman Miller Mirra. Pricey, for sure, but provides better support than anything else I've ever tried.
- Massage sessions with a specialist experienced in hand issues. I go to various places every month or so and it "tides me through"
About 2-3 years ago it used to hurt every time I typed - now, I get stiff hands in the evening but while I'm in "full flow" it really isn't a problem. The problem never quite goes away though (at least in my experience) i.e. you can mitigate but not cure it. It's like a nagging ache in the distance most of the time, and only becomes a strong close-up ache on the odd occasion.