So I'm just sitting doing something and randomly my brain just starts showing me disgusting pictures of things I've seen in the past like unflushed shit,shit stains etc.And I just don't know how to make it stop I've been suffering with this from last 4 years or so and sometimes it really affects me and I can't really tell anyone about it because of how weird and disgusting it is.So I came here for some help and I don't know if it's a Mental disorder or should I see a therapist for this?