I realize its been awhile since you posted this, so maybe you’ve found your answers, but since nobody responded, I just thought I would.
First of all, your story is a rather typical one for many people here. You had a bad experience with weed and now you feel stuck in this sort of spaced-out, zombified nothingness state. Welcome to the hell that is DPDR.
I’m interested in why you brought up trazodone though? You seem to be implying that perhaps that had something to do with you developing DP? It is certainly possible. But I think having a generally anxious, introverted, or sensitive temperament, combined with weed, is often all it takes to send some of us veering off a cliff.
The term “antidepressant” is simply a marketing term. Trazodone was initially sold as a treatment for depression, but they noticed that it mostly just helps with sleep, so that’s typically what it’s prescribed for today.