I think that "dissociation" is the broad term for the different ways people mentally distance themselves from the world because the world is too anxiety-producing, unsafe, sad, or what have you. I used to think dissociating meant kind of blanking out, staring into space and not being mentally present, but I've read that there are other ways this can happen. One of them is to obsessively think about intellectual topics, for instance. I do this myself a bit, I kind of write essays in my head at times and I have trouble putting it aside until it's perfected. What you tend to do sounds very imaginative, and probably has been adaptive in some ways if it's distanced you from the world, but maybe it's become distressing in some other ways. A lot of defense mechanisms are like that-- they do work to an extent, and they also hold us back to an extent.

I'm no expert on mental health either, but to me this sounds like a dissociative coping mechanism and I don't think it means you're "crazy," I think it's just a technique you've developed to make life more bearable in the face of abuse.

Emotional abuse can be as harmful as physical and even sexual abuse according some research. Humans are very psychological animals and sustained emotional harm is devastating. If you're able to start "processing" what happened -- whether by self-help or therapy or through friends or writing -- I would imagine this need to pretend would start to lessen. If it's bothering you, I would try to find a therapist maybe.