Assuming you are real, and have experienced an orgasm, I'd suggest you have de-sensitised that part of your body, or most likely you have not found a man that you have loved, trusted, and talked to.

Obviously your body MAY have a physical defect, but it is most likely between the ears. Sounds as if it's too late now though.

It is possible to have one with the minimum of stimulation, if in the right frame of mind, as is the opposite.