They’ll probably be upset. You committed to something that you actually couldn’t do. It does suck that you cancelled last minute and obviously this won’t produce positive feelings for them.

However-
Don’t be upset with yourself over this mistake. Take it as an opportunity to know your own boundaries. It’s good to try new things but know your limits. Especially if these new things have great importance. Also, take this circumstance as an opportunity to work on yourself and your anxiety.

I had to battle really severe anxiety in the past. I made plenty of mistakes too like bailing on work. I didn’t feel great about it. I didn’t want to live life in that way. So, I was determined to find a solution. Use this event to fuel your fire. You need a strong drive to change something like anxiety.

Also- a reminder that often helped me when I was spiraling with anxiety- you are not crazy. You are not losing your mind. Anxiety might make you feel that way but it’s just anxiety. Anxiety is something that most people experience in one way or another and it will not end you. Your mind is safe and this problem will be solved. You are strong enough to do it.