In 2010 my current wife and I gained custody of the two kids, now 14 and 12, and we have a brand new life in our family who is just over 9 months old.

When you say your current wife and you have custody of your two kids from your previous marriage, what occasioned this and where is their mother? What sort of relationship do you now have with their mother? Could your feelings and inability to relax with your current wife revolve around your past experiences with your previous wife and other experiences?
Daily I worry for the safety of my young sons - but worry achieves nothing! So I pray for their safety!