Worm (2013)

In a future where we no longer have the ability to dream, people have turned to "Fantasites," a genetically-engineered parasite that induces the user's wildest fantasies. When one socially-awkward young man begins to use this new miracle dream aid, hoping that it will bring excitement to his mundane life and get him closer to the girl of his "dreams," he soon finds the line between reality and fantasy squirming away.