I (24F) breakup with my partner (24M)?

Hey everyone, I need some urgent advice. I'm at a complete loss about what to do next.

I've been with my partner (24m) for 2 years and a half and we are each other's first serious relationship. We started dating in our final year of university. Honestly, our relationship has always been full of love and friendship, he's the only man I've ever genuinely liked.

The core issue is that our needs are vastly different: He can go days without texting me and be completely fine, but I like to be in regular contact, even if it's just a quick message to say I'm busy. For most, if not all, of the relationship, we've had countless arguments because he simply doesn't provide what I consider the minimum effort for a partnership, like showing interest. I'm always the one who has to remind him about our plans, and I'm always the one making the plans so we can see each other.

A few months ago, my grandfather passed away very suddenly. I felt like he was not there for me the way I needed him to be. I called him having a panic attack when I found out, and he didn't text me back until a day and a half later, even after I had written to him again. To top it off, he told me that attending the funeral seemed "too personal" to him.

After that, I gave him an ultimatum, as I felt his reaction showed a severe lack of consideration. He admitted I was right and apologized, which he often does, but he always reverts to his old behavior.

The absolute final straw happened two days ago. He told me his manager was making him choose his last available week of vacation. He had to choose between the last week of November and the week of December 15th to the 21st. Mind you, we don't live together, and due to our work schedules and the distance between our homes, we haven't had matching days off in four months, so we only see each other once a week or every two weeks.

As it turns out, I didn't get to choose my vacation; it was assigned to me, and I was given the last week of November (until Thursday). I told him this, hoping he would choose that week so we could spend time together. He did not. He picked the other week, December 15th-21st, where we don't have a single overlapping day, as it's the week after my vacation.

When I brought it up, his response was, "Are you trying to argue again? I chose the week that seemed best to me."

It's not about the week itself; it's that he seems completely indifferent to our time together. I have absolutely no energy left to keep trying to communicate to him how one should behave in a committed relationship. He did something similar with his summer vacation, prioritizing his own wants and needs over coordinating time off with me.

I urgently need advice because I can't continue like this, but I also don't want to rush into a decision or regret it.