How To Loosen Up A Tight Vagina During Intercourse?

Hi Doctor, I am 27 yrs old and my WIFE is 24 yrs. Our marriage was 1 months back. We have not been able to do intercourse any time. The problem is that the penis is not getting inserted into the vagina though it is erect. Looks like the vagina is tight. We are very much worried about this as we are looking forward to having a family soon. Pls advise