Sex drive

My boyfriend and I have been together for a little while now. I’ve always been the one to start the fire. I’m often thinking about having sex with him. He is normally into it once I get him interested. He takes anti depressants I wonder if it’s that or is he just not really all that interested in me? When I ask he says he says he finds me very sexy and thinks about it all the time. Why doesn’t me ever start things??