When to end it when you have kids

Hey everyone. I am looking to leave my husband of nearly 18 years. Long story short he rotates between being emotionally abusive or ‘doing his own thing’ but expecting me to hold everything together behind him. Yhis has gone on for several years, but the moments when he comes at me emotionally and mentally have increased exponentially since laat summer. The last few months have been incredibly stressful with him and I literally moved into the mother-in-law suite attached to our house just to get some space away from him. For context, he is the sole income earner, we have kids, and I have had a lot of medical crap the last two years and am on 3 prescription medications. Ideally I would like to walk away the day after my oldest graduates high school and avoid disrupting her last year with her friends (she is a junior now). But my husband is on a 1-2 times a week binge of berating me for my decisions/actions/life goals/etc. I don’t know if I can even last a whole year from now. What would you do? How did you make it work until you were ready? I really want to find a job or have some income and get my own health insurance before making a move. Our other kids are younger and would not be as dramatically affected as the oldest one. So basically I am trying to wait a year to save money/become financially independent/not disrupt my daughter’s “golden year” of high school.