How do I share my "real events" with my new OCD therapist? I feel so much dread.

Had my first session with him last week and felt truly heard for the first time. My biggest theme that I struggle with is real event OCD, and I think it's important(?) to share what the events are so that we can progress, right? If so, I feel so much dread about sharing these things.

Like, I just met this dude last week. He's now hearing the absolute worst things I've ever done. My mind says he's going to be so disgusted by me and he's going to drop me as a client.