Planning a breakup?

I am planning on leaving the father of my children. He most of the time treats me and the kids like shit, has anger issues. Right now he's acting nice which is making it hard but I need to stick to my decision cause I know it won't last..

So we have a trip planned to go see his family a few states away at the beginning of august and I am planning on ending it when we get back... Is that bad to wait so long ?

I just don't trust him taking the kids without me . And I can't ruin they're first big trip .

Just need some advice I guess. I'm 30 and have been stuck in this relationship since I was 18, I've never dealt with a breakup.