Penis Problems. Reason, infection?

Hi doctor, during masturbation my foreskin swole. My doctor gave me medications saying its infection. Swelling went away away. But after one month when i masturbated it swole again. Doctor gave me same medication. Swelling is gone now. But i have weird veins on my foreskin. Which get very thick on erection and even on flaccid state they are noticable. When my penis returns to flaccid state from erection veins stay swolen for a while and they are thick.When penis erects i feels very hot in my entire penis and my penis head turn very red (unusually red). Also my foreskin turns very red. On erection i feel like ejaculating instantly. Also my testicles feel very hot during erection. I feel little tired these days too. What could be the possible reason, infection ??