Can i delete all my data from my broken iphone?

Is there a way i can get into my phone and delete all the data? I mean from a website of something? Its completely broken, and won't even be identified with itunes, so i'm not sure if i can even delete all that stuff? I have some texts i don't want my brother to see, and i need to erase them before he takes my phone in tomorrow while i'm at school.

He can't read them you are fine my buddy did the same thing and had some texts that he wouldn't want his mom to see haha.

Brake that disgrace of a phone even more to make sure haha.