This might not help you but I too had couple of thumb injuries while keeping this season, few weeks ago ball hit flush on the tip my thumb and thumb was swollen for couple of weeks , I still played every Saturday with pain and kept wickets as well , now the swelling has gone away and I can't fully straighten that thumb , i'm not sure what happened but it must have been a fracture or some sorts but I didn't feel massive discomfort while batting.
Then the same happened with my other thumb last week(bottom hand when batting), but this time it was very painful while batting due to vibration of the bat, I taped the finger with a home made splinter for the entire week, now the swelling has gone away and I can fully straighten the finger without any issues.
So probably best to go to doctors and get an x-ray or some sorts to check it out, or at least do what I did with a splinter.