Wow, it's been ages since I checked this thread...sorry to everyone for leaving it so long to reply! Thanks for all your support.

I don't think it is carpal tunnel, because as watchthestarsfall says I get symptoms in my arms as well. I have a "tennis elbow support" that puts pressure on tendons just below my elbow, which can help sometimes and makes me think it's more of an issue with tendons than anything else. I've been tested for arthritis and inflammation and that came back negative.

Personally I think RSI is most likely, which might also explain why it didn't really show up at orthopaedics? It gets worse when I do anything repetitive, like typing.

I'm considering going back to the doctors again, but I'm getting more and more convinced that this is caused by my trichotillomania (compulsive hair-pulling), because the hair pulling has been bad recently and I'm now starting to lose some feeling in my fingertips as well as the usual stuff that I mentioned before. (Not all the time, fortunately, just when I'm doing anything repetitive.) If it is the trich that's causing it, this basically means that I've brought it on myself because I've been to three therapists to try and stop it and it hasn't worked (well, it did the first time, but the second time didn't help at all and the third time only helped for a couple of months). So if I tell the doctor this I really don't know if there's anything they can do - suggesting I go back into therapy again isn't much help (especially since I'll be going home for the summer in a few weeks and I'll never hear the end of it from dad if I go back into therapy again ), and if orthopaedics is right then even if I do by some miracle manage to stop then it won't make the RSI or whatever better, it might just stop it getting worse...

So, essentially, this is my own damn fault.