Hear, hear. The fans no doubt spent years crafting their own version of how things will end. Whatever he does decide on, some -- if not most -- aren't going to be happy. Especially since he's dragged the series out for so long...
I'm actually excited now that HBO is, more or less, in the creative front seat. The audience is in infinitely more control over the story progressing versus the story ending. Figure 10 seasons through the end of 2020 and Game of Thrones will be over, then Martin is free to take 20 more years to rewrite the last four seasons of the show.
Just put the keyboard down Jade. Nobody wants any trouble. We just want to talk. It doesn't have to come to this. Now let's not do anything we'll regret tomorrow. Put the fluffing keyboard down. Shots fired
Just let it go. If you are not having fun doing it, there is no point. Give yourself a rest, start a new project. I have left unfinished a couple of large works and I don't mind. Maybe later in life you will be able to finish.
Like many others suggested you don't need to write everything in order and you don't need perfection the first time around. I have several areas of my WIP where it goes chap. 1..2..3..4..then a paragraph explaining 5 & 6 skip to chap 7 then maybe 8 is just a few words ...etc. If I find myself thinking about a scene that isn't needed until later in the book I write the scene anyway. Things can be filled in later. You might also find that when you write later chapters it will give you a better idea of what needs to be in those earlier ones. As of now I have 95k written and about 5k of that is the ending. I'm looking to hit about 120k, so now I need to just fill in the gaps to make the ending possible.
Could it be that you have more than one story to tell? Try breaking your story down to episodes that could stand apart from each other, and work on each episode one at a time. You can add the connective tissue later; the focus right now should be telling a single story as well as you can. It might work...