My fiancé won’t sleep with me anymore!?

Hey friends! So the beginning of our relationship was so hot and fiery but after a few months it stopped.. we have been together for 2.5 years now and have a baby together. I know it’s hard to be intimate with a 7 month old around but even when my mom takes her, there’s no sexual attraction or activities. We have sex once about every 3-4 months but I want it more. If I try to rub him or get him in the mood he always refuses. How do I get him to make the first move or just be into me again? Im open to anything so please help a girl out!