All those other songs have been compressed and limited to death until all the dynamics have been squashed out of them. Your song actually has dynamics, soft and loud, which is a good thing, but it keeps you from turning it up louder without reducing the dynamic range. You could try some compression and limiting if it's really important to you, but I wouldn't recommend you use much.
This has been the bane of the music industry for years. Human beings perceive louder songs to sound "better" or "fuller" than softer ones, so idiotic audio engineers and mastering engineers have been constantly battling to find ways to make their songs "louder" than all the other songs on the radio, so that when their song comes on, it sounds "better" and "fuller" than the one that just played.
All of this has resulted in music that sounds dull and lifeless, since it has no dynamic range (the difference between the loudest and softest parts). This is a slippery slope. Once you start competing with everyone else's squashed compressed songs, you'll just keep doing it more, and you'll be losing quality and life in your songs the whole way.