19 is an adult so time for them to move out and pay their own way if they’re failing in education. It’s a tough life so you have to make tough decisions for them.
This is about life choices. If a 19yo wants to waste the education opportunity then you need to give them a raw alternative to jolt them to make the right choices. You’re there to be a parent not their friend.
Pulling the rug out from your child is not the way to help them become self-reliant. If the expectation up until this point is that they would get financial support no matter what, you need to transition to a point where they’re self-reliant. You should still push at every step, but that is too big a change to tackle all at once.
