Hi, I'm so sorry to hear about your tough year. You've been through a divorce which must have been a traumatic experience. Could it be that you are having trust issues due to the broken marriage? Its perfectly understandable that you don't want to have your heart broken and feel vulnerable again. But your boyfriend has stayed with you throughout all these difficult times and actions speak louder than words.
Do you have a social life apart from your boyfriend? I know its difficult to spend time apart, but doing things that make you happy or/and spending time with your friends can be very rewarding. It might also gives you the chance to view things from a different perspective. Also, have you ever told him what is going on in your mind and why you are so anxious of losing him? Maybe it would help to have an open conversation. Take care