Rejection? (reposting off anonymous)

Lenie 🍄 • Sex positive, body positive, here to learn and teach, taken 💍
So I'm a 23 year old woman, I've been with my boyfriend for almost 2 years and we have a pretty healthy sex life. But it feels like almost every time I initiate or ask if he wants to have sex he says no. His reasons are valid, stress, ate too much, too tired etc. but it's getting to the point where I want to stop asking and I almost never physically initiate because he shuts me down so much. Yet when he's in the mood, and he's all over me, even if I wasn't feeling horny I let my mind go and we have sex because I want that intimacy with him and I know I'll enjoy it whether I was previously "in the mood" or not. Of course I say no if I really don't feel good or something but most of the time I get into it, sometimes I think because I know if I don't it might be a while before he's in the mood and I want to get it while I can. It's gotten to the point where I feel like we only ever do it when he's in the mood...but when I expressed that to him he said I've painted him into a corner because I have sex when I don't want to and expect him to as well. But to me it's sometimes about letting what's on your mind go and being there for your partner...especially if they haven't orgasmed in 9 days and he did the past 2 days...I dunno am I being petty? I of course want him to want to have sex and I don't want to be selfish but I feel a little let down. Thoughts?