Am I (18, female) harboring resentment towards my boyfriend (20, male)?

Hello, I’ve been experiencing a sense of indifference lately, and while it’s a long story, I really need some advice, so I hope you’ll bear with me. In September 2024, my boyfriend and I had a significant argument. At that time, he was heavily involved in soccer and was struggling to focus on our relationship. This wasn’t the sole issue for me, though—I was dealing with a lot. My parents were going through a difficult divorce, my pet bunny had passed away, and both of my grandmothers were in the hospital. I was mentally overwhelmed and desperately needed reassurance. I reached out to him multiple times, asking if we could talk, and while he initially agreed, he ultimately canceled on me. That’s when I really lost it. I sent him a detailed message expressing my feelings of being unwanted at home and in our relationship, and how neglected I felt. His response was heartbreaking: he said, "It's nothing you did, but I think our arguments have affected me. I don’t feel the same way anymore, and I wish I did." He mentioned enjoying our time together but feeling worse more often than not, and he conveyed that spending time with me made him want to hang out less, which completely blindsided me. I felt betrayed and wished he had shared his feelings sooner. I ended up apologizing, and we moved on. However, that conversation lingers in my mind. I often wonder how things would be if we had broken up instead. I’m terrified of experiencing another surprise like that and hesitate to ask him to spend time together, fearing that he might not genuinely want to. I find myself mulling over the argument almost weekly, especially whenever we hang out or when our anniversary comes around. After that fight, it felt like I went through a breakup. I distanced myself and didn’t really want to spend time with him, even though I still love him deeply. Now, although we seem happy together and my love for him hasn’t changed, I can’t shake the indifference toward our relationship. I’m not normally one to hold grudges, but this incident affected me profoundly, and I feel like I had to conceal my pain from him during my healing process. I’ve realized that I won’t be able to move on without discussing this with him, but I’m hesitant to bring it up since it happened months ago. I really need clarity and closure on this situation, but the hurt still lingers. I’m reaching out for help on how to approach this conversation. Any advice would be greatly appreciated. Thank you!