Thanks so much for the replies.
I'm really hoping it's not arthritis, because the pain came on so suddenly (although I have had it a couple of times before). What about the swollen wrist, though??? You can actually see that it's swollen! The reason I'm stressing about it so much is that two doctors (!) told me that perhaps I have early onset arthritis (osteo or rheumatoid)..they said it so calmly, just based on my symptoms, while I was freaking out!!! I think that perhaps now that I'm even more worried about getting arthritis, my joints hurt even more ??? Or maybe it's just a coincidence..?
Anyway, thanks to all of those who replied.
Also, I know that for rheumatoid arthritis, in addition to xrays, they do blood tests for C-reactive protein and check the Erythrocyte Sedimentation Rate..I had a couple of blood tests on Tuesday, but I'm guessing they wouldnt've included that?? I don't know what blood tests they were..I think just full blood count, etc. I had an infection (tonsilitis) a week ago, so perhaps the joint pain is also related to that?? Argh, I do hope it's just stress induced!