Boyfriend always refuses when I initiate sex

Every time I initiate sex my boyfriend always comes up with an excuse not to do it…

We will have sex once every ten days or so and he will be the one to initiate but its like, does he only initiate it at that time because he needs relief ? Because every other day he doesn’t want any of it !

It makes me feel insecure and shit about myself. I don’t think he’s ever wanted to have sex when I’ve initiated. Could that mean I just don’t turn him on or he’s not attracted to me?

And as an example. Tonight I got him to massage me , I stuck my ass up and tried to make it sexy and fun and tried to initiate and even said come on I’ll suck your d….

And he said “no I’m tired” … yet now he is staying up all night playing video games?! He is 31 by the way, not 17