I think unfortunately you do need to have a lot of pre-emptory remarks prepared. The key things to cover are to establish your self-awareness and then discuss some of the triggers of your difficult behaviors and how you want others to feel empowered to address them.

This isn't one-to-one with a cluster b disorder, but I struggle a lot with compulsively making mean comments. With new friends, I have a short speech explaining it, how I share my true thoughts, and encouraging them to directly speak to me if they feel upset or offended. Sadly, it doesn't work all the time and more people bounce off sooner, but the people who do stay around it has been possible to build more secure and healthy friendships with.

It might be helpful to find a similar process for yourself.