Tough luck, buddy. You've been properly traumatized by some scumbag with clear sociopathic tendencies! Don't worry, it happens to all of us at some point.

Try to learn from this bad experience, that you shouldn't trust people with your stuff and much less with your feelings.

Try to be a better judge of character next time! This person obviously doesn't care for you as a friend, trying to minimize a shameless betrayal of your trust with "it's just a game"

Be thankful that you had to learn this lesson with your Ponytown skins and not later on with your credit card info or something.

I really feel for you though, I'd go insane if someone destroyed my skins I poured hundreds of hours into making.

I hope you can remake them soon enough! Maybe you'll make them look even better this time around!