Originally Posted by HgaleK
I think a modified Nil's text might be your best option. Something similar to "I won't be able to make to make dinner on Wednesday. I'm sorry for the erratic behaviour. I'm in a difficult place right now and need to take a step back and figure a few things out. This will be last contact with you for a long time. Please don't try to contact me.
Then you have to live up to it. No FB, no phone, text, call,...