Depressed and in need of some comfort

So my mother messaged me on Facebook a couple weeks ago asking me to think about my youngest sons father (I call him a sperm donor). He is not in my son's life at all. Well my parents are getting my son tested cause he is in special needs classes most of his school days. So now my mom wants me to think of anything my ex may have had that could have been passed down to my son. It breaks my heart that there is something wrong with my son. All I have been doing these past two weeks is reliving every moment from my past with my ex. I have had nightmares every night. I feel so guilty like it's my fault my son is like this. I feel like I could have prevented this but didn't I feel like a horrible mother. I am currently married to a wonderful man. But he doesn't like to hear about my past so obviously I haven't told him what is going on. And I really don't have anyone to talk to. Anytime I have had an issue I have looked to my glow sisters for help. So here I am turning to all my glow sisters looking for some comfort. How can I make these feelings go away? I love my baby Connor so much and he and his brother are the light of my life. It just breaks my heart that something could be wrong with my baby boy.