Hello, about 5 months ago i got hit on testicles the left was and still is swollen and the pain is starting to come back. what should i do?

Go to ER or your doc: Need evaluation by a physician to make sure the injury did not cause damage , or did not have torsion ( twisting ) You may need a sonogram

Trauma to testes: Go to ER this morning to make sure no torsion of testes (can be intermittant / pain is severe) . Sometimes after injury or even infection there is damage to lymph vessels and persistent swelling but pain is more serious. Make sure there has been no twisting ( torsion) so go to ER this AM for that and they can check for infection as well. Afterward f/u with urology for varicocele/hydrocele