As I read slush, I'm reminded of a tip from a famous editor: utilize try-fail cycles. A try-fail cycle is exactly what it sounds like. Your protagonist tries something (usually to solve a problem), and is not successful, and then tries something else... Most authors write these organically, without ever thinking Now, I need a try-fail cycle. It can be helpful, however, to consciously think about them.
Consider a definition of a story: a protagonist has a problem and acts to solve it. If the protag acts and is successful, a try-succeed instance, this is not an interesting story. Is it even a story? If the protag merely acts and fails, a try-fail instance, again, this isn't an interesting story. Thus, the cycle aspect of the try-fail cycle is also important. The protag needs to try more than once.
Most interesting stories have a series of try-fail cycles with increasing stakes. This makes the story more dramatic and gives the reader a more satisfying emotional payoff in the end. Try-fail cycles show and enable character growth. They also allow the overall story plotline to twist, change, grow. They make a short story much deeper and more interesting.
So, if your story is dragging, consider adding another try-fail cycle. Good luck!