sexual frustration

In August 2015, I reached out to a therapist in fears that my sex life had spiraled out of control. Through deep discussion and raw, painful honesty, we came to the conclusion that I was a sex addict. 
I gained control over my life and my actions over the 3 months that followed, and then I met a guy who swept me off of my feet. We had a healthy sex life and a blooming relationship. We are now engaged, but after moving in with him our sex life has slowly dwindled. There is no more passion or romance. I've tried talking to him to figure out what has changed, but that gets us nowhere. It turns him off if I'm ever the one to initiate anything sexual. He doesn't like kissing or cuddling, or even being touched. We went from having sex 4-5 times a week to maybe once or twice a month. He has a two year old son that we have for two weeks at a time. We used to find time for play, but it just doesn't happen anymore. What should I do? Is this normal? I'm trying to think of ways to bring back the romance and flirtation that we used to have. 
Productive comments only please ❤️ this is a sensitive topic and difficult to reach out about.