As you said that both of you love each other and it is well known to both of you then in this case you should not hesitate that muc and simply you should go ahead and ask him about his problem due to which he can not trust you. See trust is very important in a any relationship so I think you must make him understand if he has any kind of doubts in his mind. By this you can make your loving life happy.
Enjoy..God Bless..