finger splint

Easy to use, wrap a stretchy bandage above and below the finger (not to tight!). Then secure the shorter end to your palm with a soft wrap. Use ice every 20 min and ibuprofen to reduce swelling.
I am not a doctor, so go see one there are a lot of things ( like ligaments and bone splinters) that can go wrong in the hand.
Good luck and hope your day gets better :)