Hi titus,
Slight correction: SOMETIMES people with personality disorders don't know they have one.

Just like sometimes "normal" people have no idea of the impact their actions have on others.
BPD isn't black and white. Many people have traits of BPD, but not to an extent that it
severely interferes with their lives and the lives of others. When the traits become severe enough, that's when they start qualifying as a "disorder."
DBT has worked for a close friend of mine with BPD. I have personally not been through it. However, DBT is not just for personality disorders. It's also "a treatment for severe and persistent emotional and behavioral difficulties, including personality disorders, affective [emotional] disorders, substance abuse, eating disorders, suicide and self-injury." In other words, it doesn't automatically mean that you have a specific personality disorder. What DBT does, in essence, is re-teach someone how to function better. It's basically very structured self-improvement. It teaches "core mindfulness, distress tolerance, emotional regulation and interpersonal effectiveness." This is a beneficial thing to learn for everyone who has difficulty tolerating stress, i.e., most people, with or without a personality disorder.
Here, check this out:
http://www.dbtselfhelp.com/index.htmlHere's a simple explanation from the same page:
http://www.dbtselfhelp.com/html/what_is_dbt_1.htmlI have BPD. (Surprise!

) I know I have it. I'm self-aware. That's the key. It took me a long time to become aware of what I was actually doing. So recovery is possible.
Self-awareness is important no matter what you're going through. It was less important for me to actually get the diagnosis 8 years ago. I thought, "OK...I
know my emotions are all over the place...that's nothing new." What I didn't realize (i.e., was not self-aware of) was that, even after I got the diagnosis, I was still raging on people, regularly driving 95 mph through icy and rainy weather and self-medicating with alcohol. Once I actually realized that I was doing all of those things, that's when I started taking them individually and working toward stopping those behaviors.
That's what "mindfulness" is. Remaining self-aware.
If you have more questions, feel free to post.

I'll tell you how it was and sometimes still is for me.
--Frayed
DBT is actually my next step. There are still things that I feel I need to work on.
Do not take my advice before talking to your doctor/counselor/other professional. Depending on where you live, you may be able to find free, confidential care. Most importantly, sometimes your shrink can be wrong. Get a second opinion.