there's no need for bad parenting or bad childhood to develop a pd. My parents were just arguing a lot basically, but nothing abusive. It has created trauma anyway (no need for abuse to create trauma). Read the resources (right panel), especially this one that you can probably find on the internet.
Ironically, some things don’t have answers. Even when we seem to think we have found an answer—or a drug—to solve our problem’s. Maybe now it is time to start a book. You might find useful... https://www.amazon.com/Divided-Self-Existential-Madness-Psychology/dp/0140135375
I’m sorry I don’t have a better answer for you. I could go into the pharmacology but I don’t think that’s the answer you need right now.
Be well :)