Am I crazy?

I really need to know if I’m crazy for this or if there are any other moms that have this bad of anxiety about their children. My son is 3. He will be 4 next July. I still constantly check on him to see if he is breathing when he’s asleep and I still use a video baby monitor on him at night. I was terrified of SIDS happening with him when he was an infant, so bad that I wouldn’t sleep for hours just checking to see if he was breathing. SIDS isn’t even the only thing to worry about because there is also sudden unexplained death of a child that affects children aged 1-18. I’m just so so so paranoid about it and it’s getting worse since I’m pregnant with my second son due in January. It’s got to be unhealthy.