From what I've read this is a common side effect of anti anxiety medication and one I've experienced myself.
I found it helpful to focus my mind on aspects of intimacy such as the sensation of skin on skin, the closeness & warmth of another human body against mine and the emotional connection that intimacy brings. I found side effects of my medication eased a little after I had been on the medication for a few months. I have continued with the same medication for 10+ years and found it very helpful. My dosage has changed to suit stress levels, and getting dosage right (with doctor approval) can help with side effects including this one.
Glad you posted, this is a problem I think many of us have and your post will help :-)