@confusedadult
I'm sad and confused as to why so many posters seem to say LTB without even trying.
As a family, you need help.
I don't condone ending a marriage when there are kids without trying- and I know you aren't at fault.
But as a family, you need help. There are organisations where you can get help- yes, it's parent /family coaching, but there are some great options out there for parents of teens. Your DH should access these if he wants to save his relationship with you and his DCs.
Ok, you might have to suggest this and show him the way forward, but that might be better in the long term than breaking up your family.
Yes, teens say they want their dad to leave, but teens are very good at saying things like this, hating one parent or the other, playing them off against each other.. it's what teens do.
You don't have to do what your children say and in some ways it's passing the buck to act on their wishes. YOU are the adult and you have the chance to change things.
You need to sit down with your DH and explain very calmly how bad things are, and that you will split if he does nothing to change.
At least give him the option, but make it a proper grown up conversation, not a threat or a shouting match.