I would be alone if not for you
Submarine (2010)
If you smushed together Harold & Maude, early Woody Allen movies and Rushmore, you’ll get Submarine. It’s not necessarily a bad thing, but it’s a bit too precious and twee.
Of note: the director is Richard Ayeode who starred in Garth Marenghi’s Dark Place and the IT Crowd. So that’s kinda cool!