Whenever we (rarely thankfully) have a disagreement he always turns it into a massive, unending, unresolvable argument. It just goes round and round in circles because he will not listen. He always resorts to ranting and shouting really loud and I think he does this to make me shut up. Like he wants to intimidate me into not 'challenging' him We never even really fall out and when we do it's usually over something minor, which makes his behaviour even more worrying.
He won't listen to me no matter how reasonable and calm I am and eventually I become enraged because he won't let me speak. Everytime I open my mouth to speak he'll say something. If I manage to begin a sentence he'll interupt. There really is no point in me trying to put a point across but my silence doesn't bring the conflict to an end it just leaves the floor open for him to rant at me. On the rare occasions he actually stops long enough for me to say something he still isn't listening but rather managing to keep his mouth buttoned long enough for me to finish and then he continues ranting at me.
Last night, after telling him over and over that he wasn't listening to me he raised his arms in the air and waved them as if at a football match whilst shouting 'I AM LISTENING I AM LISTENING I AM LISTENING' at the top of his lungs. Honestly wtaf?!!?!?!?! Later he asked me to explain what the problem was and I said, 'ok' and without missing a beat he began talking instead of me!!!! Later still, he resorted to trying to manipulate me emotionally by wallowing in self pity and accusing me of ruining the night which eventually became 'You've ruined my entire life!' Again, WTAF???
Clearly his behaviour is ridiculous and it's damaging our relationship. I lose so much respect for him everytime it happens and I feel like I can't have a disagreement with him because this will happen. He also behaves in the same way if I'm feeling down (again thankfully this is rare) and isn't great if I'm annoyed/angry about something outside of our relationaship, so I don't feel like I can go to him for emotional support either. It's as if I'm not allowed to be anything but fine and happy.
Every time this happens I consider ending our relationship and this time I really am considering doing this very seriously. Though I don't relish the idea at all!!!
Why is he like this and how can I make him see what he's like if he won't listen to me in the first place. I'm at my wits end. 
P.S> When we first met I casually asked him why his ex left him and he shrugged and then told me that she'd said he didn't listen.