Rejection.

So about a year ago my boyfriend and I went thru a tough patch. I was basically begging for sex, walking up to him naked and still getting turned down.  He and I got past it (was his self esteem issue) and are fine now. But I haven't gotten past this new developed fear of rejection. I don't ask for it , I don't initiate it and I don't beg for it. And it bothers him that I don't initiate it. He also works long days 13 hours 6 days a week and if very tired so when we do have sex he complains that he is SOOO tired and didn't get enough sleep so than I feel guilty ( he doesn't blame me straight out). How do i get past the fear and start initiating it again like I use too