You’re really not going to get rid of him. He doesn’t care he is very very entitled and abusive.
He has the measure of you, he knows you’ll be too scared and polite to actually throw him out.
Really, seriously, call around friends preferably big male friends to come round and back you up. Start packing his stuff in bin liners, tell the teens to call their mum and pack their stuff as they are leaving.
If you don’t, you will still be cooking, cleaning, ferrying around his kids and paying for this cocklodger and his offspring for years down the line. And they’ll all enjoy treating you like a doormat.
I bet your dc don’t like having their mum, and their home over run by all these strangers. But they, like you are trained to put everyone above their own basic needs.
If you can’t face going home because of the people staying in your home, then remedy it.
Stop being nice. Stop worrying about everyone else, when it’s you who needs to be put first.