After quite a stressful period in work about 5 years ago I started suffering with anxiety, intrusive thoughts and obsessive thinking. It was scary as the thoughts were upsetting and I felt so out of control. I didn't even know what to name it so couldn't describe it to anyone. My GP called it pure O - as in OCD without the compulsive behaviours. I had online cognitive behavioural therapy which helped loads and I can manage it much better when I'm triggered.