Frustration/annoyance/worry - aren't these the adult ways of feeling upset? I can imagine I would feel the same if my parents divorced.
They too don't have a relationship I would aspire to - but I hate the thought of them splitting as I couldn't have my "family" any more the way I'm used to, and we've never moved house so that would make it even worse.
My sympathies anyway. In a weird way, I have sort of long prepared for my parents to divorce, it just hasn't happened! I don't think they will, they are too used to each other. But my reflections:
Just give yourself time to adjust, and your parents time to adjust.
They won't live together anymore, but in fairness your childhood of living with them was coming to an end anyway. Particularly when you find your own serious partner, you're going to have to divide up Christmases and holidays anyway, not just spend them with your parents. You might feel more like spending those times with a partner in future - in one way this will make that easier! So that change wasn't far off in any case, if that's any comfort.
Maybe they will each be happier now and you will actually enjoy their company more. If they find new partners you might be able to get a new sense of family with each of these - but like having two.
In time your parents may acquire a friendship with one another, they may actually get along better than when they were married. For one that could be nice to see, but also I wouldn't write off ever spending time with both of them together again. I know divorced couples who have moved on enough to be comfortable with one another (and usually their new partners too) and they can spend time/events together, particularly when these involve their children.
It will be much harder if the divorce isn't mutual though.
Best of luck anyway.