What Causes Low Libido And Tightness Of Vagina In Women?

My wife age is 32 yrs but she does not able to do sex and she have no excitement for sex. The vegina of my wife is very tight then penis does not enter properly. I want to treatment my wife but she is not agree with treatment. I have trying many time to check-up for Doctors before 2.5 yrs but my wife not willing to check-up of vagina and not willing for PV test every time. Sir, Please help me.