i think it’s okay to diagnose yourself with ocd as long as youre serious about it and do a fair amount of research! also i’m sorry your mother is like that, that isn’t fair of her at all and you deserve better.
i don’t know your fiance so i can’t say for sure whether you should tell him, but i do think that if he’s open minded and has an understanding of how ocd works, he Should understand that having pocd doesn’t make you a dangerous person.
would telling him about your pocd make you feel more comfortable or make it easier for him to help you? you dont necessarily Have to tell him about your pocd if you dont want to, but if you think it’ll help you, i don’t think you should bottle it up.
its okay, youre not an attention seeker, you’re just trying to understand what’s going on. what you’re describing kind of sounds like hypochondria, which is its own mental illness, but its really similar to ocd and its not uncommon for people to have both. however i cant say for sure that you have hypochondria OR ocd because im not a therapist, but it does sound like what you are describing so i would suggest asking a therapist or doctor about it if you’re able to