What would you consider betrayal or breaking your trust?

I would like to get some understanding on how big or small deeds can be seen as betrayal, how do you react and what would make you want to forgive.

Recently I did not show up when we agreed to meet with this 8 man that I'm interested in. I did this because I believed that he was arranging me a nasty surprise. He had earlier that week been a bit nasty to me so I thought he'd do something similar again. This talk that we were supposed to have was important for the both of us and I know I hurt him when I didn't come. Partially what I did was because he has been asking me to react authentically. This is authentic me and I own what I did. I'd be lying to the both of us if I tried to hide that this bothered me. But I still feel bad that I hurt him.

At the moment he may understand why I did this but he's been avoiding me (which is his normal reaction). We aren't close enough to effortlessly talk things through but we are (were?) trying to get there. He's a romantic interest to me and I hope he will answer my feelings if I get another chance to tell him that. I believe he likes me in a romantic sense as well.

He's put a lot of effort in getting to know me little by little and I feel like I owe him a lot. (But I also have consistently been there for him for months.)

Is this something you'd consider unforgivable?

Edit1: As long as he's avoiding me, I can't provide him with any explanations.

Edit2: I don't believe anymore that he was planning me a nasty surprise but I realized that a bit too late. We are both quite stressed out and agitated at the moment. Affects our ability to interpret each other's intentions.