My children are 7,6 and 2, and i still go in and check to make sure they are breathing.
Almost every night before i go to sleep, a vision will pop into my head of what 'could have' happened during the day. I just have to shake it out and think positive happy thoughts.
Each time i was pregnant, I worried about how i was going to protect that baby from danger.
I probably haven't helped you at all - but just wanted you to know that it's part of the Mummy job description for us to worry about our precious bubbas.
Take care