What happened to the boy who would shatter every time I was hurt?

The answer is:

His back used to face me and now he changed his mask and decided to turn.

When I fight back, it enrages you more. So you choose to slap me with your words, making sure they damage my core.

After all the fighting, the kisses slowly start to come.

One by one, like bullets from a loaded gun.

We disagree on so many things, but this is what we have in common.

Nonetheless it is the epitome of all our problems.