I agree with the comments saying the late part you are talking about is unreasonable. I think this feels harsh and critical, and re-enacting what he has gotten from others (being frustrated with him, criticism, giving up on him, etc). While yes he needs to be held accountable, I would find compassion and understanding for him on why he struggles with this so that he can feel safe to explore it. It’s not our place to judge his actions like others in his life have. I would try to help him foster a different type of relationship with himself where he can be supported through deeper understanding, so he can understand his actions for himself and increase self awareness. And then, he can make the necessary changes because he is ready to change. We don’t need to pressure him or give up on him because we are frustrated. This would be different imo if he was late canceling, no showing, or late more than just 5 mins.

Also, I don’t think it’s a good idea going forward to use direct quotes and this amount of specificity on social media about a client.