Keep yourself occupied with things around the house to keep your mind off of your husband. I know it will not be easy at first but once you get caught up in your own projects you will not have time to be thinking about him. Also, you can join some social group to help you with your free time or just sit down and read you a good book. There is no magic tricks to help you with trust, either you have it or you will have to develop it. But, you can learn to become comfortable when your husband leave because there is nothing you can do to prevent him from doing whatever, it is that has you nervous. Just hang in there and try to focus on yourself.