The tip of my dick hurts and its hard to cum do I have a infection?

Probably. Haveing penile pain and difficulty with ejaculation is a sign of infection in the urine or prostate. These need to be treated with antibiotics or may need lead to a chronic condition. See your physician for testing and the appropriate antibiotics. Be sure your partner (s) gets treated at the same time so you do not reinfect one another.
Likely, UTI or STD. Need to get it checked. Good luck.