There are many good websites on this, and a great book (by Pascarelli, listed on the sites):
http://www.tifaq.com/ - Typing Injury FAQ - start here!
http://www.rsi-uk.org.uk/ - home of the RSI-UK mailing list, with many good resources that aren't limited to UK residents.
I managed to recover from RSI completely a few years back, but it took quite a lot of time. See a doctor ASAP if you haven't done already, and take it seriously - early pains from using a keyboard/mouse are indicators to do something now to avoid problems later. Even if you have continuous pain, you can recover, but you need to start getting treatment (and the right treatment) ASAP. The websites have a lot more on this, including stuff I wrote a while back.
Hope this helps...