I just wanted to add that it is entirely possible to dissociate without switching. You can definitely dissociate without having other identities. This wouldn't mean you're just sitting there like a zombie either. You can dissociate, have conversations with others, carry on with tasks you're doing, but not experience what's going on without having alters that come forward. There are also lots of reasons why a person might black out. You can black out from panic attacks, for instance, or for multiple medical reasons. I have had some completely bizarre conversations with my gf that she has no memory of when she has been hypoglycemic.
I hope that doesn't muddy the waters further for you. I still agree that the most important thing to do is to work on identifying triggers and learning how to work past them in a way that's healthy for you. The fact that you've been working on grounding skills and seeing improvement is great! Being able to ground myself has been vital to my being able to get through my days.