I can tell you I was married 17 years and it wasn't a perfect marriage and we never fought to that extent. I'm not sure where the fights we had came from fully in terms of the intensity of them. I think they started out as "normal" fights, but she would invariably start crying, or lashing out, name calling etc, and I would then get more frustrated and ramp it up, etc. I am trying to look at where those feelings came from and I went to counselor last week and plan to continue.
Good move! Working through all of that in the wake of a breakup can be very beneficial, a period of profound growth, and good for you! And of course this site is a great resource too.