Shitty sex drive?

My boyfriend has an insane sex drive. I enjoy it every once in awhile but we just went on a week cruise together and he constantly was pushing me to have sex. It frustrated me so much and I actually found myself having no desire at all to initiate or engage in sexual activities. Every time we’re together I feel like I’m actually finding every way I can to avoid it. I feel so bad bc I don’t want to make him think it’s about him... I just don’t understand why I have no sexual desire? Anybody else going through this :( Let me know if you have any experiences/ advice. Thanks so much!