Self pleasure during sex

My boyfriend and I have been together for about 8 months, he doesn't allow me to rub my clit during sex (if I try, he pulls my hand away)... its the only way i can get off and it feels amazing. He saying it's disrespectful to him, like he's not enough or that I don't like him (which is not the case). I've tried to explain this to him but I think he's insecure. Am I wrong? Is he? What's a girl to do?