What in the hell are you signing that you've just be learning for ten minutes to have your hand hurt already!? SOS! MAYDAY! Seriously... I can use my hands in a lot more awkward and uncomfortable circumstances other than signing and not have issues. Shouldn't you be learning words like chicken, duck, fast or maybe the alphabet?
Your hand hurts over fingerspelling? ummmm.... wow, not sure as I've ever heard of that as a problem.... I hope it's not a lasting one for you, as there is an a$$ load of fingerspelling in ASL...
Arthritis does make it harder. Do you take medications for the arthritis, my mom puts warm pads on her hands but idk fi that works for everyone.
It's a new activity where you're trying to do things with your hands that are very different from things you've normally done up until now, right? And are you practicing with alot of intensity? I mean going at it non-stop, maybe working pretty hard?
I'm not a medical professional, but just from my own experience, I'm thinking maybe you've just strained the muscles in your hand a bit? Or maybe cramping up? I'd try backing off a slight bit: take a break, and when you get back to it continue to practice but in short sessions with breaks. Also, pay attention to how much tension you're using in your hands when you make the shapes of the different letters. You should be able to do them without grimacing. Try to see if you can relax the muscles in your hands as much as possible while doing the shapes.
I say this as an extremely intense person who goes at everything as such, and sometimes your body complains:0
Good luck!
Another thing, if your hands get sore and you need a break but your mind still wants to practice, I find it to be very useful just to *think* through the handshapes. It's surprising how effective that is as far as improving whatever skill you're working on.
You just have to practice
Funny Workout Finger!! Lol - YouTube
Your hand hurts over fingerspelling? ummmm.... wow, not sure as I've ever heard of that as a problem after 10 minutes.... I hope it's not a lasting one for you, as there is an a$$ load of fingerspelling in ASL...