Middle finger pain when weighted, like when i do pull-ups or just hanging and the base swollen.i got it after doing repetitive hand-grip exercise.

Avoid exercise : You could have a tendinitis on the finger, tendon or ligament injury ,or a bony injury (less likely) . Rest the finger by avoiding the exercises movements that make you hurt. May apply cold compresses for 15 minutes to the affected digit 2-3 Xday. See what happens. If there is no improvement then you will need to see your doctor and possibly be referred to a sports medicine , ortho/hand specialist