Initiating sex

So I have had 3 other partners before my current boyfriend that I was sexually active with. I never relized that they always started the sex and I never really had to. Well now I have this boyfriend that has had to initiate so many times he feels awkward. So jokingly he said he was going on strike,assuming I would suck it up and things would go back to normal. I did not even relize that I'm so horrified to initiate sex. Once the sex or anything sexual starts I'm fine and we do our thing. But now I just lay in bed trying to give myself a pep talk to have sex with my boyfriend who obviously wants to have sex but thinks this dumb strike will help me. Its been 3 months now since we have had sex and it sucks. Not just because I enjoy sex but he does too and I feel like that is a part in someones relationship that should be good. He doesn't complain but I still feel horrible about it.Any advice? Rather you have had this issue or not. Just anything would be helpful.