Initiating sex

So I have been with my boyfriend for 2 years now and I have this huge fear of initiating sex. I know that I should feel comfortable enough by now but I just cannot bring myself to do it. We have talked about it many times and I think my biggest fear is that I'll put myself out there and he won't want to have sex. His response to that is "I'm a guy. Why would I say no?!". I believe that this fear comes from when I was with my ex. The last year that me and him were together we didn't have sex once. The first 6 months of that year I would always try to initiate and always got rejected. Even though I know that the amazing man I am with now would not do that, I just can't seem to bring myself to do it. Any suggestions??? Please help!!!