How come he doesn’t want to see me?

I’ve been with my boyfriend for 3 1/2 years. Things were going very well until May, when he had to watch his parents house when they took a vacation in Europe. Since then, he’s chronically canceled plans on me. We had a big fight about a month ago and he got really mad at me. Since then, I have only seen him twice. We are now on a break and it’s been a few weeks. His behavior confuses me. He’ll go completely silent, then he’ll text me like things are back to normal. This has been on and off for a few weeks now. I have been wracking my brain trying to figure out what may be going on. I have attempted to ask him and he won’t answer any of my questions. I don’t think it’s only our relationship problems that has kept him away. We go from texting like everything is fine, to his going completely silent on me. I’ve tried to get him to open up. Yesterday we were talking like everything was just fine between us. He asked me by text at midnight if I’ll go to Europe with him to visit his family. This morning I sent a usual good morning message and invited him to dinner. It’s been silence all day except for his response, “not today, sweetie.” Nothing, just that. What the hell is going on? This is how it’s been for a couple weeks now. We talk like things are fine, then silence. I am not sure what to make of this and I have thought that something is going on in his life that he’s trying to deal with.

He’s the sort of person who shuts down when he’s dealing with things. But since he has not communicated to me what’s really going on, I have no clue and I’ve been left confused. What could possibly be going on with him? I know. Most of you will say to dump him. Sometimes that’s not the right thing to do. How do I proceed with this?

Updates
1 y
I forgot to add, twice now he seemed willing to see me and talk about things. We’ve made plans with a time and when that time comes, he’s mad and says he doesn’t want to see me. He gets mad at me, when I haven’t done anything. I think he’s mad in general and is taking it out on me.
Updates
1 y
We had the fight 2 months after he started canceling all the time. That’s what caused the fight.
How come he doesn’t want to see me?
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