Lost

I'm lost... I am completely unable to see around the next bend, and it drives me completely crazy. School has become mediocre as I wind my way through the final semester of my BA... My relationship is good on so very many levels and yet it is lacking in one of the areas that defines me as a person. Sexual tension is boiling over and I don't know what to do about it. We have been living together for nine months, and stopped having sex approxiamately five months ago. She has lost all her drive and nothing seems to be working to bring it back. So I am left in a frenzy of masturbation and anxiety. She swears she is still attracted to me, but just has no want to have any sort of sexual activity. This is where I get lost... attracted to, but not wanting sex... I don't understand... maybe it is a testosterone thing, the reason why I can;t understand it... Sex is an integral part of who I am, and I am terrified that there is a pattern repeating. My marriage was like this. We became rommmates rather than lovers. But in the marriage, we didn't discuss it. because she didn't want to discuss anything until it was too late to fix anything. At least in this relationship we discuss it, but it isn't getting sorted out. There simply are no carnal relations.... and when that hapens... my mind starts to wander... and my gaze... at any other point in my life I may have ended the relationship, or might have started fooling around, or began to find ways out... but I don;t want this relationship to end... I want it to be complete...
I hate not knowing how to fix it. She has talked to the doc abotu it, and was on anti-depressants for a while but she did not find that they were helping her, so she has stopped taking them... but has not gone back to talk to the doctor again, either... this is all fine... it is her body chemistry and she most assuredly has the right to dictate what she does to it. But I guess what I am not seeing is an effort to make things better, to get it back to where it used to be.
I do understand that there is a certain rate of diminishing passion, I expect a little of it, after the honeymoon period is over... but... not for it to stop altogether... I am having a very difficult time reconciling this and I really am at a loss as to what direction to turn, and how to discuss it further, beyond where we have been. I am trying to be a patient man, I really am, but damnit I am getting tired of the twice daily visit with my rght and as well. There is only so much porn can do for you... anyone have any thoughts, similar experiences, fixes?