Ending , the 180º turn by the Queen of Dragons

I used to feel the same. Then we went back and rewatched the whole thing and on the second viewing it's much easier to see how she spends many seasons losing her seelf to her inevitable true nature. She was always almost as bat-shit crazy as her father.

Considering that almost throughout the entire series, they would mention the insanity of her father and the strong possibility that it was passed down to her, combined with her traumas; then it was no surprise the writers gave her a 180.

She was incapable of knowing the "reality of the real world" only after the death of her two children and a couple of friends/allies?

The woman who was married off by her brother and raped by her husband?
The woman that was nearly imprisoned for life in a tower by a consort of wizards?
The woman that was looked down upon by everyone she came in contact with (save for those she liberated)?

I think she had a pretty good idea of reality by the time the loss of her children and friends rolled around.

It's been made clear by the author that the intention was to have her become a maniacal dictator after coming into power over a long story arc. I suppose it might have worked on the show had they taken more time with it. Going back and watching the series as it stands . . . not so much. She displayed the same dogged determinism every other would-be claimant to the throne displayed -- only with a wish to break the wheel and be there for the helpless.

To show her losing her mind suddenly and murdering women and children, en masse, throughout the city just doesn't fit.