Ok me and my girlfriend have been going out for a month now and we started having sex. Well we gradually built it up. The problem is i cant stay hard while having sex and i have no idea why. I mean she gets me hard from just making out with her. And she has no problem getting me off froma blowjob (which by the way are Awesome). But when we start actually having intercourse I am hard in the beginning then i put on the condom and it starts to go down. We start screwing and it stays hard for a while but as soon as we go to change positions im done. We are using the ultra thin trojans and it really feels great but I cant keep it hard enough to cum. We are both each others first and she is getting to where it really feels good to her but she gets dissapointed when i dont cum and thinks its her but i know thats not true i mean she gets me hard from a simple kiss. Im thinking about trying a supplement or something. Anyone have any recommendations I was reading about horny goat weed anyone use it before and have opinions. Please help I dont want our sex life to be bad everything else is perfect. Thanks.