What is the causes of quick ejaculation while having sex, what should be the treatment` bcos its embarrasing?

Premature ejaculatio: Much of this is felt to be related to emotional issues around sex. Reassuringly, it's not usually related to a concerning medical problem. It can be caused related to medications. While it's unclear what would be optimal to treating your issues without examining you in person, things like sex therapy and desensitizing agents(it's why some condoms contain mild anesthetics) are often utilized.

You mention...: You mention infections. Increased irritation can act as a sexual stimulant (for example, leading to use of various minor irritants for increased sexual effect). Given your reported background conditions start by having infection/inflammation evaluated.