feeling like my 9mo relationship is at a dead end

Me and my partner have been together for 9mo but they are unable to talk about their emotions with me or express them, and so they often come off cold. It makes it hard to feel like I can go to them about my feelings when they tell me nothing. They would cancel nonstop, often to hang out with a friend, and would try to make it up, but never directly say sorry. I felt like I couldn't rely on them to be there for me emotionally because I could never count on their word.

It was rare that they would ask how I was doing or about me. But I have my number of flaws, and I had a difficult time addressing things in the moment and would wait a few days later to address it so that I had my thoughts together. Multiple times, I told them to let me know if I had done something that hurt them, and they said that I hadn't and that they would. I never felt as close to them as it felt like they and their friend were, because it felt like they were always so willing to throw our plans away.

They are also asexual, so for a while, it was me initiating basic relationship things, but it did get better. It felt really unnatural at times, especially when people kept asking me if we were still together and it's not to say that everything was on them or they did nothing right, but it just sucks. I've had multiple conversations with them and I'm wondering what I should do in this situation? I don't know if I should ask them again about opening up or just break it off.

tl;dr Partner is emotionally distant and I'm unsure if I should ask for more or break it off.