Planning a escape

I’m in the process of leaving my husband. He cheated on me and I took him back but he just covered it up even better this time and talking to other women sexting them. So my plan is to finish school and get a apt with my son and the new baby. My parents are on board with me and will pack my things while he at work. So I have one year left of school. I can’t financially support myself right now due to school and living with my parents is not a option due to Space. I’ve tried leaving him before but he talks me out of it and I just feel miserable when we get back. This is the best plan for me. My internship offered me a job when I finish school so I will good pay to support my kids and me. When he home, I’m quiet but it’s like he don’t care because I’m still there. I reject his kisses and sex. I just don’t want him anymore. I know he still cheating on me because he hides his phone. But I can’t leave. My parents have my grandma who is terminally ill living with them and can’t support me. After seeing that he is a cheater. But my question is:

How do I play like everything is okay until May 2019??