Mirrormirror,
I can relate to your fears of secrets being shared as retaliation. In my case this fear was never realized, and I think it is because I also know my pwBPD’s (a sister) secrets, and so she kept her mouth shut.
It is very wise of you to seek out support. Do have a counselor, or would you consider getting into counseling if not? It would be helpful to find a counselor who has experience with people who are trying to leave abusive relationships. You might also want to preempt any attempts by her to begin a defamation campaign by having a chat with your HR department, as well with your friends and family, but I would recommend that you speak with a counselor before you make any moves. You might even begin to avoid any major drama if you start putting your foot down with her and start standing up for yourself so that she is the one to pull the plug on your friendship instead of you. This is the strategy I used with my sister.
I would also encourage you to attend some Codependents Anonymous meetings as these can also be very helpful, especially if you work with a sponsor.
Most of all I would also like to reassure you that you are not abandoning her. Only dependent children and those that are physically dependent on others, such as the disabled and elderly, can be abandoned. You are simply ending your friendship, which is something that millions of people the world over do on a daily basis. She is in therapy and her therapist will be there to pick up the pieces. You absolutely deserve to find sanity, and I wish you much strength and courage.
