Dissociation and memory

Hi. I'm having a tough time. I had therapy today and I'm just not sure I can handle it. My head just barrages me with horrible things I should do and I can't concentrate and stay present for work or my son.
I froze in session. It happens all the time and I can't say or do what I want. I'm starting to freak out a little that maybe I do have some trauma. I've been having these pictures in my head of something quite specific and I'm not sure if they're memories or just thoughts. There's not much context about them so I don't even know what to make of them.
Then I found out the other week my therapist has diagnosed me with DID which I don't agree with but then im freaking out because I know there are things about me that aren't right. That wouldn't happen if I was ok. Like my desk got moved at work and now my backs to the door and I was nearly in tears over it because I felt so vulnerable not being able to see. Even just the change.
Im not going to lie, I think I already struggle enough with my life as it is if I had something else I think I'm just going to be done. I don't want to stick around to find out.
How do I know what's real and what's my imagination and how do I survive knowing and how do I stay present. Even though I don't think I have other personalities I do struggle to stay present