I don't think libido is your issue, it sounds like you have a self esteem issue that makes you not beable to enjoy sex. It's actually pretty normal for a woman. I know since I have put on weight, I don't feel good about myself... therefore I don't get fully eroused, because I'm to focused on my appearence or performance, then the sex sucks. I'd say 60-70 percent of the sex I've had in my life was not enjoyable... not because of my partner, but because of my self esteem.