NEW CAREER FOR MUM

Hi IM’s.
I’m in my early 40’s, a married mum with 2 pre-schoolers and am wanting a new career.
I’m currently a project manager which requires me to leave home at 6:30am and get home about 6:30pm and be on call at night and weekends. It’s sucking the life out of my family and my kids miss me, I miss them.
It’s not the type of job that can be part time or job share, it’s a male dominated industry, I’ve spent the past 12 months looking for better conditions in my field but it’s not going to happen. So… I want OUT! I do not have a degree, just spent 15 years moving up the ranks in my company (which is NOT family friendly)
Due to my age I don’t want to get stuck in Uni for 4 to 6 years, but could study (and would probs love it!). I have NO idea what to look into that would offer me the flexibility, shorter hours I’m wanting for a decent pay range.
I understand I’ll have to take a significant drop in salary (currently $140k pa) and can afford to drop down to about 70k a year.
But how? Doing what? I’d love this next career move to last for 20+years.
Love to hear some idea’s/direction and advice.
Thanks in advance 