Think about the story of Chicken Little. What if you took that story, but made the characters humans instead of animals, and made the fear be about meteors destroying the earth instead of the sky falling? Well, you'd have what would feel like a completely different story, and yet it would be exactly the same.
There is a classic argument that, if you dig deep enough, there are only 3 stories: man versus god, man versus man, and man versus himself. Even if you don't agree, it is unarguable that there is not a great deal of overlap in stories. Use that overlap to your advantage.
Start creating stories by analogy. Write the story Baby's Day Out, but the baby is a senile old man. Write Rocky, but he's a chef instead of a boxer (this might make the scene where he's punching the beef carcass hilarious or disturbing). Try writing Die Hard in an office building.
When you can't come up with anything on your own, be a great artist and steal. Retell a classic story with new specifics. Nobody will probably know. You may diversify. You may not. That's up to you.