Hi Darren!
Only last year a therapist diagnosed my depression. Only then I understood a lot of simple symptoms that I had had most of my life, including isolation. She also showed me that my mother was depressive in my childhood, helping me to understand her distance.
I also think it is wise not to talk about it to people in general, because most people can't or don't have the time to understand and that will make you feel worse (usually we hear something like "you should forget it and go on with your life"). But if you have someone you can trust and that proves capable of listening to you without judgement, DO talk to this person.
This is the place to talk about it. DO whine, but don't get lost in it, look for the causes. What is the motivation behind it? In my case, I learned that I whine mostly because I feel inferior and complain of people and situations in general to try to be at the same level or to feel justified.
Regarding your feelings that you have your own disorder, remember the basic facts: if you were really disordered, would you be here and in therapy, accepting your problems? No. Really disordered people don't see anything wrong with themselves. So, the very fact that you are questioning your sanity is your first and very concrete sign of sanity.
Of course we don't grow up or live with disordered people for years and then go away intact. In my case, I have lots of traces of NPD, that I am working on. And living with this kind of people is crazy-making by itself, we have to learn what normal is in the aftermath and that takes time and experience.
Hope I helped.
Best wishes!