Is there a word for preemptive regret?

For example, having had long standing plans to attend a late night event, I suddenly realized that I was really tired and it will not be a good idea to attend. While I made the decision to not attend the event, I was filled with regret, despite still being able to attend despite being tired.

I usually understand regret is a feeling about something that happened in the past.

What would you call a feeling that happens about something that is about to happen in the future, where you in theory can avoid it, although perhaps not in practice (since there was some reason to avoid it).

In the situation you describe, I would use regret with no qualms. This is perfectly fine, for example:

I’m already regretting my decision to stay home tonight, but I really am too tired to go.

The thing you're regretting is your decision to stay in, which is in the past, so there is no problem.

There's also the colloquial (though not yet dictionary-codified) pregret, which is specifically knowing that you're going to regret doing something that you haven't done yet; but I don't think that quite fits the situation you're talking about here. It's usually used in pretty much the opposite scenario of yours here: going out drinking when you know you'll be kicking yourself for it in the morning.