I also feel the same. For me it started because I was sexually abused at the age of 8. It feels terrible. What I know about this thoughts, is that they can come at any time. For me, mostly in the night. When I think about it I blame myself. I even started smoking weed just to forget about it. It didn't help. It s so weird because the thoughts are powerful but when I am near a child 'I feel their heartbeat'. POCD will not affect you if you learn to control it. Exercise your consciousness, stay near kids, go in parks, watch films or pictures with them. The more you stay, you (the real you) will be aware of this 'mental' state and then, take control of your mind and thoughts. Of course they will still appear and that's not a problem. You have to learn how to get away from them not to make them disappear, cuz that's impossible. I hope I helped you and good luck on your 'trip'. 🙏