I've recently been diagnosed with AD(H)D and have been depressed for around 5 years altho I'm still in my early 20's. Lately I've been obsessed with figuring myself out and basically wanting to answer the question; what exactly is wrong with me?

I've probably wiki'd about every personality disorder and read as many articles as I can just to figure out what it could be that I suffer from.
When I was reading about DPD, just like when I found out I had ADD, I had this little "a-ha" moment and actually felt relieved.
Not only because I recognise the symptoms but it just fits the story right. It makes logical sense to me.
I feel like I can fill in an answer to all the questions I had about my own actions or inactions in the past.

Does anyone know what could happen when you suffer from the 2 (ADD and DPD)?
Could one of them intensify the tendencies of the other?
How do the two disorders generally blend together?