So, so sorry you're going through this.
I guess there is no sugarcoating it so here it goes: I agree with others, you will probably break to pieces, but more importantly at one point, sooner or later, you'll start putting yourself back together. You will never be the same again, but I guarantee you'll be better, as you'll be survivor.
I know it doesn't feel that way at all at this point, but it is true: what doesn't kill us makes us stronger. It will not kill you. It will feel like it is killing you, but it won't, as we all have that survival instict deep inside, and once it kicks in it is stronger than anything.
From my experience: I was falling to pieces for years, being miserable all the time living with my A ( our circumstances were a bit extreme with him having liver cirrhosis and nearly dieing from it, infidelities, stealing, you name it, all but physical abuse) but at one point when I truly felt I'll die from it all, when I felt I have no more room left to manuvre to excercice my pain and other overwhelming emotions, when I truly couldn't take it any more, there was no more rooms for anything, thinking, words, feeling, nothing, just that survival instict that made me do whatever I needed to do to get off that floor and stay alive.
So IMHO you'll feel the pain and agony for only as long as you can take it, not a minute less or more. It will be hard but once you get off that floor there will be no going back there.
You can help speed up this process, you can work on yourself, dig deep as you can and try to find answers to questions: what made you stay so far, why do you still love him, and most importantly why do you feel you can't live without him. All those answers are in you. You just have to find the way to figure them out (SR has helped me figure all those things).
All you have is you, and I know that sounds terrifying right now, but it will come the time you'll see that is the good thing, and there is a good chance one day you'll look back at all this and think it was the best thing that ever happened to you.
Hope at least some of this makes some sense to you.
HUGS