Is there a reason why dissociating is bad?

If you don't process the emotions that are in your body, they build up. In your case from time to time they release themselves in a panic attack.

Detachment from emotions is useful disassociation isn't. In detachment an emotion can dissolve on it's own. You are aware of the emotion but you don't get meta emotions. You don't do anything with it. Without a new trigger that usually means that the body can go and work through the emotions.

If there only one emotion in your system and no meta-reactions towards it, then the full processing ability can be used on that one issue. That's what happens during mindful meditation.

Instead of doing 10 things at once, there's actually rooms to really process on thing at a time.

I have no idea if any good teachers are around, but if they were, I couldn't afford lessons.

That doesn't have to be a case, it's quite frequent to have meditation events on a donation basis.