Hi-
I'm not a doctor but I think your gut instinct is right. I've been on both of those meds. They don't go well together so they can cause what you described as your symptoms. Trazadone did the same thing to me when it came to nightmares!
Don't stop the meds suddenly on your own unless a pro tells you it's ok to. Even though it's a low dose and a new one. Can you call or page your therapist and tell them the reaction your having? They can start tapering you off, or let you stop completely, depending on how sensitive you are to the drug and what's going on.
I hope you feel better soon!