It started when I was about 12 - puberty was the trigger, physically.
No idea about Vit B8.
It manifests itself invisibly - well, most of the types do. I have had several, including visible and invisible.
What's it like to live with? I'm alive, and that's what matters at the end of the day. Sometimes that has been hard enough. Imagine the most disgusting thought or image you can - now, it's flashing into your head all the time, uncontrollably. Imagine the thought 'I'm going to kill my child' and that thought never, never going away. See the knife. See the baby.
How frightened are you now? How frightened are you after five hours of it? Five days? How do you keep safe? Should you go to the police station and turn yourself in? Where is it? Do they even have local police stations any more?
That's what it's like, uncontrolled. You are drained from fear, weak and numb from pain and fright and tiredness. You are more tired than you thought it would be possible to live from.
The most helpful thing anyone can do: don't be frightened too either from the symptoms or the horror.
It is a terrifying sickness to live with, and completely harmless to others. The only person OCD wants to kill is me. Stay calm.