Anxiety about the what ifs.

Before becoming a parent I never had anxiety, I now have a 4 year old and a 2 year old and notice at night once in bed I have a really hard time with anxiety. I cannot help but to think someone is going to break into our home, my house will catch fire, my kids could pass before me, or even I could pass at any given time and they wouldn’t have their mother around. It literally keeps me awake at night. I have trouble falling asleep because I cannot control the impulsive thoughts about what if. I feel so alone like I’ve never heard of this before.. please if anyone has the same issues comment. How do you help these thoughts?! It drives me insane..