Question

What should you do if your finge got hit hard by a hammer and your finger becomes black while bleeding

Answer 1

Go to the er if it’s horrible you’re not gonna have a finger

Answer 2

Put ice or a cold pack on the finger for 10 to 20 minutes at a time.

If the skin looks cracked or is bleeding, the skin may be open and may need stitches. Seek a doctor if there is significant or worsening pain, redness, or swelling.
(like in your case)

wrap it in something hold pressure, and go to the doctor, they will check if you broke a joint/bone.