Virtually No Libido. Possible Hormone Imbalance?

Rachel
So it's strange. I had sex with men for about four years. I've recently become more comfortable in accepting my sexuality and have been with women for the last few months. I feel more comfortable and more eager to please women than I ever have men; and it honestly feels more natural. 
But the problem comes when either gender has tried to please me. It's like I don't feel anything when they're down there. Even with me trying to explore on my own. There's just nothing. I'm 23 and have never reached an orgasm. It's frustrating for me. It's frustrating for partners. Has anyone else dealt with this? Any advice?