conflicted and need advice

I recently had an argument with my boyfriend, and it's left me feeling sad and conflicted. He opened up about his concerns regarding our relationship. he mentioned that he felt like I wasn’t happy with him, and, he also expressed that he feels that I'm no longer attracted to him because we haven't been as intimate lately. Just to give some context, we're in a long-distance relationship.

I explained to him that I've been going through a tough time lately due to some family issues and stress in general, which has caused me to act differently than usual. He genuinely believes that I'm not happy with him anymore, and despite my efforts to explain, it seems like he's not convinced. No matter how many times I reassure him that he makes me incredibly happy and that he's not failing as a boyfriend, he doesn't seem to believe me. It's incredibly frustrating because he truly does make me the happiest person on the planet, and I wish he could see that.
I'm afraid that he thinks I'm hiding something or not being honest with him.

I'm now stuck in a dilemma. I'm torn between keeping all my feelings to myself to avoid making my boyfriend feel like I'm not happy with him or continuing to be open and honest about what's going on with me. It's a tough spot, and I'm not sure which way to go. I don't want to push him away by not sharing, but I also don't want him to feel responsible for my happiness, especially when I genuinely am happy with him.