Another thing that comes to mind is derealization. I have depersonalisation/derealization disorder, and I believe my symptoms started around 12, as well. I'm not saying your description matches my experience perfectly, but when you say "truman show" it makes me think "derealization," that's all. It might be something to consider.

I agree that it is good to keep an open mind when going to a Pdoc for a diagnosis, but sometimes I do think it can be helpful to share your own thoughts on what's going on, as long as you don't let it cloud your judgment too much. Sometimes there are a few comorbid disorders at play, such as bipolar, derealization, and some assorted other things in my case. If I go to a Pdoc and mention everything at once, sometimes they find it hard to distinguish the main problems from the side issues. So I like to be explicit about the fact that right now, my main problem is my depression, just so we can stay on track and look for ways to deal with those symptoms first, before getting into things like derealization that are annoying to me but not such a major impediment to my life as the depression is.

I keep daily mood charts and journals where I keep track of all my issues. I find it can be helpful to take those notes along when visiting my Pdoc sometimes. That way they can get a clear, objective overview of what's going on, and at the same time I can point out individual things and differentiate them from other things. At least that's how I like to do it, your mileage may vary.