I agree with the two others that have replied to your query.
Like you, my parents divorced when I was young and as happy as I was to be away from the abuse, it was still traumatic. I also notice that my DPD gets worse when something bad happens.
My DPD is almost definitely the result of a physically, emotionally and verbally abusive father - much of which I have blocked out. I can remember the abusive actions, but cannot remember how I dealt with them, or if I even did deal with them. DPD has many faces and many causes. Only a professional can help you establish the cause.
In my case, the disorder is very well managed with the appropriate meds. I no longer see a therapist - I have learned to recognize when I'm about to have a full-blown depersonalization/derealization episode and medicate as necessary. For me, it never truly goes away, but it does subside and I'm able to function in society with minimal symptoms. I have noticed a timing for the peaks - typically mid autumn and mid spring.
I recommend that you do see a mental health professional - I couldn't have come this far without the assistance of my psychiatrist and the therapists I've seen over the years.