This was not the End!

The editing was going well and almost finished. All that was left to do, basically, was the final formatting for the e-book version.
Then I had a thought.  This happens to me sometimes, and I have learned to go with the flow and see where it takes me. And this one did seem like a good idea.
You see, I have this thing about endings. My writing tends to speed up as the end approaches, and this can play havoc with the tension, not to mention the dramatic conclusion of my story. It’s as if I cannot wait to get it over with. I did it with book two and my beta reader had to bring it to my attention. It was becoming apparent that I was doing the same thing with book three.
Endings should never be simple, especially in a mystery thriller anyway. The readers will be left feeling cheated if everything turns out all hunky dory, tidied away like a children’s story.
Quite apart from the fact that a tame ending will completely ruin all the other good stuff your book is full of. 
The best endings are the ones you never see coming, or at least you thought you did, but are mistaken. My favourites are the ones where you think you’ve reached the end, only to find the story goes on and bites you on the backside!
So I have a lot more work to do before this book is ready to fly. This last one has been hard, probably because it is the last in the trilogy. So much harder to write than a stand-alone novel and so much more to think about and consider. Keeping the continuity going had me pulling my hair out on more than one occasion.
I haven’t written a trilogy before but it was an interesting undertaking, and challenging too…
Has anyone else encountered this, or is it just me?