I was listening to the Writer's Panel podcast, and they had a team of TV writers and one of them said to run out of story as often as possible. (I apologize, anytime they have a panel, I make no effort to distinguish voices, so I have no idea if it was Sera Gamble, Sallie Patrick, or Lindsey Shockley). This reminded me of a workshop where Ally Carter was credited as saying, "Leave nothing behind." The idea is that if you have some great ideas, but some of them you are saving, for another book, or another chapter, maybe don't. Sure, there are exceptions, if you are contracted to write a contemporary YA romance, the time travel element might not be the right thing to toss in here. But if you figured the bomb, the betrayal, the giant reveal was for later, for the sequel, maybe it's not.
This sounds counterintuitive, but the idea make sense. First, there might not be another book if this one feels like it's just build up. And also, if you the writer were sitting there thinking, but if I use that up now, I'll run out of ideas, then that's the part you need to fight. You will not run out of ideas. Ideas are a renewable resource. And often the most interesting discoveries come when you write yourself into a corner and have to get out. And if you're too much of a plotter to put up with this nonsense, grab your post its, your notebook, whatever your plotting tool is and start planning what happens if you use up that great idea now.
You can do it. And if you get stuck, my favorite fix is fire. Trust me, I already used it in my current project.