Lost interest

So I’ve been with my boyfriend since Christmas Day (cringy I know). When we first started seeing each other it was great. I wasn’t a very sexual person but it was great with him so we did it about 3-4 times a day. It wouldn’t even matter if it was like 5 in the morning it would still happen. We’re now at the stage now where if I don’t make the effort he won’t bother. He doesn’t think he needs to. I’ve tried speaking to him about it but he gets defensive with me so I’ve given up. He says that he’s always tired . I’m not saying it’s all about sex but he’s the first person I’ve actually enjoyed sex with. I’m absolutely gutted ... has he just lost interest in me or ??