I also recommend working with a therapist. I saw 2 different therapists at the same time before inpatient to try and help my intrusive thoughts. They are terrible. SSRI's have also given me relief.

So what I have learned, observe the thought for what it is. This intrusive image/thought/feeling is just a thought, it cannot hurt me, it has no power over me. Thats just basic CBT. It can go on "Im having this thought because OCD finds my worst fears and shows them to me, it does not mean it will come true, it does not mean I am insane or evil, I just have these silly thought that I can dismiss and have no ill come to me". Get the picture?

Its like convincing yourself its just a thought and the only reason it distresses us is because we give it power. It takes months not to have every single thing distress you when you're in the pits of it, but it can be overcome. Not saying its easy, but therapy is a good way.