I'm a practicing Catholic and say the rosary most days and I am also a mother who has given birth twice. I have no problem with a virgin giving birth in a natural way. I think that some of the culture of Mary is due to celebate men obsessing on who she is. To me she was a real flesh and blood person just as Jesus was both God and a real flesh and blood man who pooped and had sexual fantasies and felt pain.
Jesus said that entertaining sexual fantasies was Adultery. Was Jesus an Adulterer?
Ye have heard that it was said by them of old time, Thou shalt not commit adultery: But I say unto you, That whosoever looketh on a woman to lust after her hath committed adultery with her already in his heart. (Matthew 5:27-28 KJV)
Be careful where you take the "fully man" part of Our Lord. Sexual fantasies, more often than not, are lustful, and lust is sin. He obviously did not sin.