I've had OCD (pure O, only ruminations, no compulsions) for as long as I can remember. It got bad after the birth of DC1.
It flares up a lot when I'm stressed, I start obsessing about past events, when I think I behaved badly and hurt someone. I imagine lots of bad scenarios, lots of what ifs. Currently struggling with images of me cheating on DH at the beginning of our relationship. I've never cheated before, but OCD is goading me really badly.
Anyone else here going through the same or similar? Lockdown has really triggered it. I feel like I cannot talk to anybody, unfortunately DH is one of those people who lives in the moment and cannot understand 
I know it will eventually go away after a while and then come back about something else.