This is a polite way of speaking of sexual relations. You may have to use other words in your translation. Alternate translation: "You must not have sexual relations with your mother's sister" (See: [[rc://en/ta/man/jit/figs-euphemism]])
The idiom "carry your own guilt" means "you are responsible for your own sin." Alternate translation: "You are responsible for your sin" or "I will punish you" (See: [[rc://en/ta/man/jit/figs-idiom]])