I just want to let you know I read your post.
It's best to take your medications as prescribed rather than messing around with them.
Dissociation is also a symptom of BPD. I don't think any medication helps with this. I learned how to ground myself in the here and now, and how to tolerate negative emotions, and that helped decrease my dissociation symptoms. I still have some episodes when I'm very, very upset but not nearly as often as i used to.
Best of luck to you! I hope things have improved since you posted.