Sexually listless, help?

For the past two months my fiance and I have notice that my ravenous sexual appetite has dwindled to a listless crawl. For some reason I'm not as excited as I used to be and during intercourse I don't feel sexual pleasure as intensely as I used to.

Something to consider: I've been weening off of Lexapro 20mg for the past 2 months as well. I need to know if this is a symptom of the weening and withdrawal or a separate problem all together. It's putting a little dent in our relationship as my fiance has become insecure and thinks that he no longer excites me (which he does) or that he's not big enough to satisfy me. It's not about size, losing interest, not getting as excited when he puts the moves on me because before these past 2 months we made love at least once a day and it was always greatly satisfying.

I just hope it's not a psycho-physiological side effect from the weening.

Can anyone help me on this?