Re-post, need more answers. Why did my partner end it after getting closer to me?

You got too close to him, he may be falling in love with you. Maybe on the trip he realized just how much he loved you or was in love with you, and was afraid to get hurt again. Nothing was your fault, it is because of his own personal demons from being heartbroken in the past. He was probably trying to run back to his ex because she might be a comfort blanket for him, and he is too afraid to really love someone new.