how can I save my relationship?

Me and my boyfriend have been together for 2 years. His father is sick so he is constantly worried and I am always supportive. But I am a bit jealous and that is where our problems begin. Now he says that he can not deal with me always nagging and complaining and he wants to break up with me. He says because I didn't take serious the times when he said that I should try to be more trusting and just enjoy the time we spend together. He never cheated on me I know that. He also has a problem that I'm 156cm and 75kg and that was the cause of my trust issues. We will talk tomorrow but he said that he doesn't see a future with me any more. I don't know what to do? I'm completely heartbroken...