Can a girl virgin grow back if she did not have sex for a long period like 4 year.is it possible that hymen grow back.i sex my bf100 times back 4 yr?

Hymen: The hymen cannot grow back. The absence of a hymen does not necessarily indicate past sexual activity because it can be broken by nonsexual activity/trauma.

Regain virginity: One cannot regain virginity, however this is not physically a problem. Try to look forward to a good future and not mull over the past. If you have continual worries about this then you may want to consult with a psychologist to help you feel better.