So sorry to hear this @LBUSH - you need to contact your Oncologist asap & get reassessed. You may need to swap AIs.
Which AI are you on & how long have you been on it? Is there anything else that may have caused the swelling/pain?
I've had hand and wrist/thumb pain - at it's worst, a course of prednisone helped me - but you can't be on it long term of there are bad side effects - like bone weakening. I found that my pain is almost cyclical - it will be shocking for a week or so & then ok for a couple of months ......
Take care xx