In the music video for Stitches by Shawn Mendes, He appears to be fighting/being beat up by someone or something. What is that?
It is love.
The song's lyrics are descriptive too: http://genius.com/Shawn-mendes-stitches-lyrics. Quoting the comments by RainbowShimmers on that page:
That got me thinking that the entire song is about his internal struggle of getting over the relationship breaking up. This was hinted at from the unseen force, as well as him being fixed at the end.
- Another site claims the same: http://radio.com/2015/06/25/shawn-mendes-stitches-video/
What exactly is beating him up? Metaphorical love.