On 5/4, i was sparring at a karate tournament and my ankle hit my partner's knee. my ankle became bruised and swollen and it hurts to walk and touch it. what should i do?

Duration suggests...: ...Possible problem. Just cannot say if bone bruise or fracture over internet. Likely best to go to urgent care for exam and x-ray to be sure do not need more specific orthopedic treatment.

Contusion vs fractur: Most likely just a contusion . Elevate , ice and rest for a few days. Will slowly resolve. If however, you hit with great force, heard/felt a "snap" and aurere unable to walkon it an xray is in order to rule out a more severe injury like a fracture.

Sparring: This was quite a while ago. You should seek medical care and x rays.