Experiencing Paranoia and Delusions - Seeking Diagnosis

I haven't been diagnosed with psychosis yet, my next session is on Thursday, but I've been experiencing intense paranoia and some delusions. I can't shower without closing the blinds in the bathroom, even though the screen on the window is one-way. And I always end up checking behind the current, before and after getting in. It's been pointed out to me recently that I look around a lot when I'm in public, like I'm watching or waiting for someone, and I do regularly see shapes of people or animals, but only in my peripheral vision. I also keep thinking really disturbing things, like I'm dead or have been for a while, or that people are watching or spying on me. Are these all valid reasons to seek out of diagnosis? All my delusional symptoms seem to be centered around guilt or depression, but I also have PTSD, so I guess I'm just curious