This isn't exactly along the lines of the ones you've already said but it's things people have said to me to add shock value to the "snap out of it"...one of those lines that makes you feel great to be alive and BPD! (More like guilty as hell when said in the right vein.)

"If you keep isolating yourself from everybody, one of these days you're going to wake up and realize it's come true."

Like that is going to suddenly make me WANT to socialize! Or, right after having an outburst or doing something stupid:

"I hope you're proud of yourself." Like you don't already feel like a wretched excuse for a human being!

Real tear-jerkers there!