learn not to interrupt or finish sentences for people

My boyfriend hates this about me and I guess it is just a habit, I don’t mean to do it but he has gotten so mad at me lately that he hangs up and says we will have no relationship if he is not allowed to speak. Help me. I guess I never realized it….SO how do we do this. Last night we were talking, I thought he was finished and started talking, he got so mad he got up and left. At times I think he is overreacting but I need tips….And when he tells me something he seems to drag the story out for sooooooooo long it seems sometimes or tells me the same thing again in a different way and I guess I have to learn to be patient, when he is getting angry at me and I get mad I do tend to jump into the conversation I guess before it is my turn and he says this is going to ruin our relationship. I told him to be patient with me. I apologized last night and said Im sorry I thought you were done, he still was furious and left. I am having a hard time trying to change when he doesn’t even want to accept my apology. At least I am acknowledging it and trying to change and this is not going to happen overnight. HELP if anyone knows any tips.