Has anyone tried NAC Vitamins for ruminating thoughts?

Or thought-stopping, or suppression. I'm new-ish to OCD treatment and recovery, and I understand and believe that I'm living with this condition, but I still don't *get* it sometimes. I don't immediately click with what other people are describing. For example, when my therapist suggests using mindfulness techniques like naming something in my environment for each sense (something I see in this room, something I hear in this moment, etc), I'm thinking, "is this thought-stopping?" because I'm using the technique to get out of an obsessive spiral and redirecting my attention outward. Isn't that a good thing? Is it thought-suppression *every* time I try to change the subject in my mind? How would you describe "thought neutralizing" mental compulsions to someone who doesn't get it? (ie me lol)

I just got diagnosed with ocd and she suggested I think about taking lexapro for it. Has anybody tried that and does it help at all?

Has anyone ever had an intrusive thought of thinking you’ve might’ve swallowed something dangerous and you can’t trust your own mind? And you feel like you need to go in to get checked out? Any advice or reassurance?