I never want to have sex – is epilepsy and Keppra to blame?

Hi everone I'm a 29 year old male who was diagnosed with myoclonic epilepsy at the age of 17. I was told this could disappear, but my last EEG showed that i still have epilepsy. So I've accepted the fact that I will have this until I die. The problem is: I've had a girlfriend since I was 21, but our sex life has never been any good. She always wants to have sex, but I never do. I just feel like it's a hassle, and just want to sleep. I've never felt the urge to have sex "right here and now". I want this to change so badly, and it was not until last year that I realized that maybe it's my medication that is the problem. Keppra has for me always been a saviour: it made me seizure-free from the first day, and I've felt fine. But now that I suspect it of ruining my libido, it's my worst enemy. Any thoughts, experiences, etc? I've also checked my testosterone level, and it's below normal. I will try to lose weight and build muscles to increase this, but never the less I know that elilepsy, Keppra and loss of sexual desire is a common thing.