We are living in challenging times, and you are definitely not alone... I have been struggling lately with focus, concentration, as I feel burned out too... A lot of things are going in the wrong direction, but that can't last forever!

I feel sometimes like there is no point because they don't listen. The things I taught before comes back again. And then I have to do it all again

My kid is now 19, close to 20... He is now a bit more responsible and (sometimes) listens... But, it was a tough job a few years ago... I thought that he didn't listen at all, but occasionally, I would catch some of my phrases in his thinking and doing... So, he did listen...
They are just in "that age", when they are always right, and we (parents) are wrong... Keep doing what you are doing as it gets through somewhere... Maybe they will not show that you were right, but they do hear things...

Wish you the best to you and your family, Zak! 💪