This will kill you Mazzymoo - but try to stay off the puter for a while until it settles down. Is it your mousing hand? Mousing can be one of the biggest contributors and you'd probably benefit from seeing a physio who specialises in occupational therapy & ergonomics who will correct your posture and positioning. Because without correcting the reason you're getting strain, you may as well not bother with any other treatment. And don't worry that you won't be able to use your hands - this is not caused because you are using your hands, but because you are using them in a way that causes tension and strain. Once you learn to use a correct posture that doesn't cause strain you will be fine. Is it mostly from computer work, or when you sew as well? Try to identify all the things that you do that cause you experience pain - generally you will find that you tense the muscles in your hand and wrist when you do them. If you can get a mousepad and keyboard wrist support this will help immensely too.

When I first got bad RSI/ borderline carpal tunnel it was so bad I thought I'd broken my hand - I couldn't lift a fork to eat. Generally this is the worst it gets - you've got to a point where it kind of reaches critical mass and the whole area has become inflamed - until the inflammation settles down all you can do is rest.