Weird Itchy Joint Pain in Thumb

For the last few days the joint in my left thumb has been noticeably red, kind of swollen (enough to feel tight), and has this ITCHY weird pain. I instinctively feel like I want to scratch it when I'm busy and not paying attention. But, when I do, it doesn't help...it just hurts. It's mainly uncomfortable when I try to pick up something with that hand, like balancing my computer to carry it to another room. It doesn't feel or look like a bruise, and I haven't done anything to bruise it. I feel dumb complaining about it to a doctor if it's something little that will go away. But I'd like to know if that's the sign of something bad.

Background that may not be relevant: Several months ago my husbands dog dragged me through the parking lot, and broke my left arm and wrist. It's been VERY weak since. It's increasingly more usable, but I still drop pots or pans if I try to pick them up without thinking. I've broken a lot of stuff around here. Several times after that, whenever I'd exercise intensely (like running in the heat), my hand would swell up enough that I had to take my wedding ring off.