Hi,
I am hoping you will all be kind to me. I have posted here before about my daughter. At the time it was looking like she had bipolar, but I never thought her behaviors entirely fitted that. Since taking a NAMI course, I am sure she has BPD also.
I am asking for urgent advice because she has just turned 18 last Tuesday and I have no clue what to do. Currently she is on Latuda, (20mg), Clonodine, and Lexarpo. Her behavior has always been difficult, but I knew it was more than just the usual teenage rebellion. She is unhappy, and has self harmed and made a suicide attempt that led to her being Baker Acted in 2015.
She has always had classic signs of being dependent on another person, and one person only, and it had to be someone who was 'pliable' and would do what she wanted. Well, for the last year and a bit this has been her boyfriend. She has once accused him of climbing in her bed and sexually assaulting her, and actually had the police come and told them. She got back together with him, and it goes through the same pattern of him behaving really badly, but she WILL not or CANNOT leave him because she hates to be alone.
The latest thing was a couple of weeks ago when he pulled a knife and threatened to kill himself and take her with him. She called 911. The police came and told her she had to finish the relationship with him, yet she went to back to him. She is going to refuse to prosecute him for it, and the state will not go ahead with it without her agreeing.
I have since found disturbing messages on her laptop to various people suggesting she is having sex with him, someone asking her if she is pregnant, and her mentioning she is smoking weed. She has quit school, college, job.
She refuses to live by any house rules, and when I get on from work she is gone and doesn't come back until late. I'm worried if he loses it again, he could stab her this time.
On reflection this does sound like a naughty teen, but believe me, she fits almost every marker fro BPD, has self harmed and threatens suicide when she argues with her BF. She cannot function in life in any capacity.
I just do not know what to do. I am trying to find her a counselor who does DBT, but its not easy to find, plus I am worried sick each night thinking will I get a phone call to say she's had an accident or something worse.
I'm worried if I do anything drastic like take my car off her or threaten to throw her out that she will get even worse.
Does anyone know what appropriate boundaries are for her?
Anyone got any advice at all? I'm at my wits end and about to have a nervous breakdown myself.

*In addition to the whole 'naughty teen' thing, I have tried taking things from her before and it NEVER went well. She always found a way round it and it never had the desired effect, like it would have had with a kid with no mental illness. I tried reward and punishment, but have found if she doesn't want to do something, she isn't doing no matter what reward or punishment is dished out.