Also, now that I'm relistening, I think this song could also be about a girl who thinks that a guy is cheating on her, so she "locks up her heart" and tries to move on. However, she realizes he wasn't cheating or really was there for her for the right reasons and she realizes he wasn't a fake all along... but now it's too late, he's already mad at her for not trusting him. If she knew that he was hers all along, this never would've happened, and now their relationship is ruined.
("Bet I'll make another mistake and think he's just another fake") This is the line that gives me that idea. She'll meet another guy that's just like him but she might make the same mistake as this time and think he's not here for the right reasons/cheating/ a fake. Also she might have trust issues but he really was the good guy... she just wishes she knew that sooner.
Also, now that I'm relistening, I think this song could also be about a girl who thinks that a guy is cheating on her, so she "locks up her heart" and tries to move on. However, she realizes he wasn't cheating or really was there for her for the right reasons and she realizes he wasn't a fake all along... but now it's too late, he's already mad at her for not trusting him. If she knew that he was hers all along, this never would've happened, and now their relationship is ruined. ("Bet I'll make another mistake and think he's just another fake") This is the line that gives me that idea. She'll meet another guy that's just like him but she might make the same mistake as this time and think he's not here for the right reasons/cheating/ a fake. Also she might have trust issues but he really was the good guy... she just wishes she knew that sooner.