To me it sounds like she fell hard for someone but the relationship was emotionally unstable and unequal. She was definitely putting more into it than he was yet she had so many expectations toward him. “I put you high up in the sky” and we all know not to expect too much from guys, because one, not to offend any guys that may be around, but it does usually take them longer to get emotionally attached than it does for a girl. You can’t rush them or you’ll only be left disappointed. And when she said “All I wanted was to break your walls” or the line “I just wanted you to let me in” She desperately wanted him to feel the same way she did for him. She wanted him to open up to her emotionally but she went about it the wrong way. I think the wrecking ball is a metaphor for rushing things, or forcing feelings that may never even grow in the first place. Feelings need to be allowed time to develop and by her “using force” or coming on too strong, it only led to destruction in the end.
It’s quite similar to my own relationship. We’re emotionally unequal at the moment and I’m trying my best to be patient with him rather than trying to rush or scare him off. Ladies, let her song be a lesson or a warning to you for your men. They need to be given time so that you may grow not only together but as individuals. It’s agonizing, yes, when you feel strongly for someone and you want them to feel the same way but it takes time and if those feelings don’t develop than perhaps it’s time to move on. However, the mistake that Miley made is she tried to force it on him or rush him. And no one wants to be in love all by themselves, believe me it’s the worst feeling ever.
I could be totally wrong but this is my personal interpretation. And everyone has their own opinions but this one holds true for me:)