5 Seconds of Summer - Out of My Limit Lyrics Meaning

I think that this song could be about being i a relationship and then realizing that after two years that its not what they thought it was going to be. "You haven't even seen the best of me", he feels like he is trapped in the relationship and cant express himself enough. But it cannot be ignored how he still sticks at it because hes loved this girl for years and is hoping to go back to how he felt before.