Boyfriend not wanting sex

I have been with my boyfriend for almost a year. We just recently moved in together, we were doing long distance for most of our relationship. Even though we were doing long distance we still would see be able to see each other every month due to his schedule for work. He always wanted to have sex whenever he saw me and it got to the point where it was a little annoying. Now he doesn't crave it, doesn't even ask me for oral. He also doesn't give me oral, I have to ask him to. It's so embarrassing when he tells me he doesn't feel like it tonight and that he will tomorrow. We have had this conversation before and his response is that he will work on it and he's sorry and doesn't know why he hasn't been wanting sex. He reassured me it didn't have anything to do with me, but it's upsetting when you feel like you are not wanted. We have a good relationship overall besides this issue. I try not to make the first move because I want him to.. Help anyone? Has anyone else had this issue?