Transgender boyfriend

1 (20f) have been with my boyfriend (20 transgender male) for a little over 2 years now. In the last year we have dramatically stopped having sex. At first I was very upset about this and thought it was me, like he wasn’t sexually attracted to me anymore. I have a higher sex drive than him and we have sex about once a month, and I’d rather once a week. Every time we talk about it he tells me he’s too depressed to have sex and he just doesn’t feel in the mood for it/desire it. Before anyone hops on the ‘he’s cheating on you bandwagon’ - he’s not. He actually is a depressed and has been seeing a therapist .. but I see no change in his behavior. Sex isn’t everything in a relationship but I feel like im not allowed to initiate it anymore bc every time I do, he turns me down and it feels like rejection. I love him so much and can actually picture a marriage in our future but I am also not satisfied in our sex life and starting to become frustrated as this has been happening for about a year now and no matter how many times I communicate that to him nothing changes. I talk to my therapist about this regularly and she keeps just telling me to Communicate that to him- which I do. But what is there left to do accept wait and hope his sex drive comes back?