Sofia.

At 15 it is pretty hard to do anything which ruins your whole life and very very few people, if any, are truly monsters and not redeemable.  I really don’t see you as being one of them.

Everyone makes mistakes, it is how we learn. And that is what matters – not how “bad” your mistakes are compared to others – but making sure you learn from them.  So if whatever you did has made you feel bad, work out why and what you would have done differently, so that you can know better next time you are in a similar situation.

Comparing yourself to others is a losing game – there is always someone better/worse, prettier/uglier, richer/poorer/smarter/dumber, you get the idea. In the end it doesn’t matter – what is important is how you feel about it and what you do about it. Feel free to share what mistakes you think you have made here, if that will help you figure out what you could have done differently.