@Wishjacked Has most of this covered, as does everyone else, but I'll add that what really helped me was forcing myself to break my story up into 'elements' and figure out what happens to each one.
We're all aware that characters needs development and the plot has to move forward, so if you consider each character, plot element, and devise a 'thread' you need to make sure you can pick up and follow each thread individually from the beginning of the story to the end. Like, if you removed all other aspects of the tale, what would the story of that one character or arc look like?
If you pick up a Harry Potter book for example, and open it at a random page, you can pretty much take any character we've already met and have a fair idea as to where they are and what they're doing at that point regardless of what Harry and the gang are up to. We know these things because Harry is forever receiving letters, hearing conversations, stumbling on secrets etc. etc, and generally being a nosy little so and so, and that's what the middle is all about- cluing readers in to what everyone is doing in weird and usual ways.
So all those ideas you're coming up with are actually very valuable and may be just what you need. Open a document and get those things stored. It's gold, I tell you. GOLD.
Next, decide what the 'story' of each of your elements is i.e. what happens to that one character, even if they're off-stage most of the time? Example: there's a secondary character in my story who helps our heroes along but also learns to relax. Simple stuff, but whatever it is you come up with make sure that in each chapter, episode, or installment of your story there's a pinch of that mini-story inside it. Or at the very least make sure that at some point, if I really took a liking to a minor character in your story, I'd be given some kind of idea as to what happens to them when their part is over.
So...you know that in the first arc (chapter?) of your story these things are meant to happen:
So, does the main have friends who are going to see her housing the enemy and take issue with it? Might one of them tell someone else out of concern? Boom, well-meaning betrayal.
What is the main questioning about the world around her? Is it whether she can trust the people she knows, or if they have all the facts? What could prompt her to wonder this? It could be as simple as an anonymous message telling her to reconsider her friends, or seeing someone she trusted do something she never thought they would.
What's the cause of her premonitions? Can anyone have them? Does having premonitions incriminate her in some way? What if she's accused of spreading the madness by people who don't believe her? I mean, how else could she know who's going to get it?
Stir that pot and stir it good. It doesn't have to be complicated but it needs to be logical, at least from a character perspective. You can do loads of exciting stuff. Play around.