Congrats on getting back on the bike!

I agree with many of the above, but I think that counseling in some form is going to be really really helpful. It sounds so much like PTSD, and that is something that really needs professional help.

He doesn't have an irrational fear, but learning to not need to control everything, that in effect nothing is in anyone's control, would help him to move past his accident and his fear of you and your children being hurt.

Best of luck