Whenever you bowl as soon as you begin you get a sharp pain at the core of your index finger near the base and persists only in that spot it only hurts when you put pressure on it what is wrong?

Probably nothing. Change your technique.

If it's really severe, see a doctor. There are diagnostic tests that can be run.

If you don't want to see a doctor and you want to stop the pain immediately, stop Bowling.

Remember: it'll stop hurting when the pain goes away.