Vaginal Burning And Pain During Intercourse.

Hi, When having sex with my GF, she finds it very hard to take my penis inside. I hurts her a lot and gives her a burning sensation even inserting my finger. Is it due to less lube? I tried a water soluble lube for the purpose but in vain. Her vagina dries out very soon. Its the first time she would be taking in. And she seems very uncomfortable with the girth of my penis. The question is she wants it, but without the pain. How could the pain be reduced? Are there any pills for that or any specific lube to be used during the initial periods? She says to get it in after getting drunk as she lose her consiousness after few and thinks it won't hurt much as she won't feel the pain. However, I dont want to, but is it the right way. She feels she is physically unfit. Should I get her to consult a doc directly or you would suggest something better? Please help, it dippresing for both of us.