Bro,
i think u should find out why she's so off for sex first before u can think of a possible solution..
She complained pain here and there, is she really physically in pain or is she trying to make excuses?
First you must understand what is the problem behind it before bros here can give suggestions to ur current situations.
Jus my 2cents worth opinion.
Hope things will work out for you soon and have sex with ur gal soon. Bless you.