Help

Not really sure how this works just reaching out for some help/advice. Dated a guy for 5 yrs. broke up because we couldnt stop our out of control arguing among other things. Been apart for about 4 years and we've sort of always dated every now and again. We have decided to give things one last shot, full force and see if we could make it work, and if it doesnt, thats it. No more coming back into each others lives. Although thats hard to do since his sister is a good friend of mine and I've grown very close to his family over the last 9 years or so. We fight, usually we are drinking, but it could be the smallest thing and we let it escalate way beyond appropriate. I try to be logical, or at least I think I do. I know it has to do with mis communication and I dot feel like he helps me improve that portion of our relationship. I dont know how to go about taking the first steps in learning to control the situation before it gets out of hand. I could just shut my mouth but then I feel like I dont get my point across to him either. I could do it, even if it wouldnt be fair. What else should I include? I could go on forever with this subject. does anyone have any suggestions as to what we can do improve on our communication or outbursts? We arent married but we may as well be. Help!