TL;DR am i the jerk for getting mad at my step brother

so i am a 15 year old femail and have a 14 year old step-brother we hate each other

but one day my step-brother i will call Jake stole my favourite tin and put his disgusting worms in it,

it was my last present from dad before he died. we got in an argument and now we aren't speaking to each other.

should i forgive him.