Sounds to me like he hasn't grown up with much of a female influence in his life and it's affected the way that he handles relationships. I am sure that you do mean a lot to him but he just doesn't know how to show it. That is why he 'comes alive' when he feels he is losing you. I think that he probably has some underlying issues that he needs to get out and talk about, and seeing a therapist might help him with that. Until then, I don't think that anything will really change in your relationship. For now it seems as if you two are unfortunately just going around in a circle.
