<human>: Me and my gf have been in a relationship for 2 years.

I recently converted from Christianity to Atheism. This is a big deal for my girlfriend because we initially got into the relationship because she would never have dated someone who wasn't a Christian like her. This is all confusing for her because now that I have changed my religion and she's already in love with me she wants to stay with me, even though it was one of her biggest points that she needed in a relationship, before we were dating.

We had also agreed to wait untill marriage to have sex, but as our relationship progressed we slowly started doing more sexual things, but there was always regret and we'd feel terrible for "falling into temptation". We were having sex regularly for about a week or two and then she dropped it on me that she wants to stop.

Recently we started to have actual sex but afterwards she always felt guilty. She says she doesn't regret doing these things with me in the past, but that now she just wants to stop and not do it again before marriage. But I want to have sex with her. I don't know how to communicate that sex is important to me, but whenever I try to stumble through an explanation she gets hurt because she "wants just me to be enough" for her. 

The atheism and sex aren't really tied together I don't think. I had wanted sex before I left the religion, and I still want it now afterwards.

What can I do? How can I communicate effectively that my desire for sex isn't just me being selfish and wanting more than I should have? 

We're also not ready for marriage anytime real soon. 2 years minimum.

Can you give me the gist of the text in a nutshell?
<bot>: I want sex, gf wants to wait. Atheist bf was dealbreaker for gf before relationship, but not sure how to continue now that am no longer Christian.