If you don't want to leave yet or can't you need to focus on SAFETY.
So avoid him when is drunk at all costs. If he ever does physically abuse you, record it on your phone and save those recordings in the safe folder on your Files which you can also hide with a pin. Document the incidents with dates and save those in the Safe Folder too.
Sometimes these things suddenly escalate so have a go bag with passports, id, some cash and clothes and hide it very well.
Get your own secret bank account and start putting a small amount of money in there.
Start counselling for yourself if you can.
Focus on your career, making good friends and doing things on your own with the children.
Put your name down on a housing list if you can do so.
Read Why Does He Do That? It's free online.
Trust your gut instinct in terms of whether you feel safe or if he will hurt you or the kids and if you think he will, get out of the house or away from him immediately.
Stay close to your family and build those connections back up if he has damaged them
None of this is your fault and you are not weak staying.
If you can leave before the youngest is 18, do so.
I am a social worker and have never seen a physically abusive father given 50/50 of the kids.
Reach out to women's aid for more advice as soon as you can.
It's scary and confusing and you are doing a great job. Stay strong!