Boyfriend not ready to have sex

Okay só my boyfriend and I have been dating for 3 years but are both virgins and I finally got on the pill só that we can have sex because we both hate condoms. But whenever we are home he never feels like having sex. He is always tired or this of that. And sometimes I try to turn him on by going down on him but even when I do that he doesn't touch me and he doesn't want to go down or me nor try to have sex after I go down on him. He told me he thinks he is not ready. We have done all preliminary stuff since the beginning and we have both gone down on each other and everything but he just doesn't want to have sex whenever I suggest. However, when we go on holidays he always wants to go down on each other but not really for sex. He only acts like that at home. He also said that its very complicated because it's hard to put his penis in my vagina and etc. Any suggestions? The thing is we have tried twice and both times we were struggling to find a good position for both and also it kinda hurt me and as soon as I tell him it hurts he doesn't want to try it anymore. By the way we are both 21 and live together at university.