I thought you already told him this is the last time before......
I have struggled with this very issue, should I write him a final letter explaining that he did not fail me, should I do the last "make sure" he understands etc....
You know what, why bother..... actions speak louder then words and I have already told him everything .... He knows what I think and feel ... of that Im sure and if he does not then its his issue because I have been open. I struggle everyday to stop thinking about him and put the focus back on me.
That is what I would suggest to you, take it off him and back on you and let him see by example your life will not stop because he is quacking again.... that your looking at action and he has a long way to go.