Enough is enough when either of you say it is. The hardest thing with love is that you do not stop loving a person after you have parted. On an emotional scale you need to know the answer to what is going on.
I say "you", as in for yourself. In every close relationship there is you and what you bring, how you react, how hurt and out of control you are. There is then the other person who likewise has the same levels of assessment. If both of you are not very functional or coping nothing is going to go well because you will set each other off, like a storm going down a street.
The other trouble is you obviously both need each other. Now what can help is to simplify your interactions, reduce the antagonism, slow down the rages, take time outs, get others to distract you and go out more, do more things apart with others. Another area is to go back to times when it worked and see what worked and why.
Does this help you?