Most stories have two plots, the internal or emotional plot and the external plot. Which plot is the primary one depends upon the genre and the writer. A lot of genre fiction (science fiction, fantasy, mystery, romance, stuff like that) treats the external plot as primary; literary fiction tends to go the other way around.
That shouldn’t stop you from plotting genre fiction from the inside out as well, though, if the internal life of your characters is where you find your inspiration. Once you’ve determined what your emotional plot is — the high points, the crises, the changes — you can start pulling together your external plot. As you do so, concentrate on finding/creating incidents and interactions that function as mirrors or correlatives to your emotional points. (Avoiding, for the sake of not being obvious, the cliched stuff like having it rain outside because your character is depressed.)
Give your protagonist external problems to deal with that a) reflect or illustrate his/her internal, emotional problems, or b) make his/her internal problems better or — this is where the drama comes in — make them even worse.
Try to keep control of the pacing so that the emotional plot and the external plot unfold at the same rate. The ideal climax should have both plots coming to their finish simultaneously and — in a perfect world — in such a way that the clockwork wheels of one plot engage with the clockwork wheels of the other to set off the bells and the gongs and the fireworks and the chimes and the mechanical knight that comes out of the clock tower and bashes the mechanical dragon twelve times on the stroke of noon and starts the carillon to playing the Toccata and Fugue in D Minor.
That’s in a perfect world, of course. Most of the time, I wind up a book feeling like I’m frantically engaged in packing an immense suitcase for a very long trip with the taxicab already honking its horn at the door and the meter running. No matter how I stuff and arrange things, there’s always the fear in the back of my mind, as the taxi pulls away from the curb, that I’ve left something embarrassing — an ancient bit of underwear mended with a safety pin, or a sock with a hole in the toe — flapping out of the suitcase like a tongue.