I think there's no question a refit is in order. Try to find a very experienced ball driller check it out. They should know what the best adjustment is to alleviate the strain.
We also tend to want to bowl through the pain which usually gets us in trouble in the long run. Get some rest and physical therapy couldn't hurt.
So 1st, get some rest. 2nd, physical therapy. 3rd refit. If you don't refit, you're bound to get recurrence of the injury. Some form of brace that others have mentioned may help, but in the end a 15 pound ball is rolling off your fingers and it will hurt if you're not healed properly and an improper fit exacerbates it.
I happen to be a clinician, but will leave further specific medical advice to your personal doctors.
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