How do you forgive someone who gives you the silent treatment?

I was wondering how do you forgive someone who gives you the silent treatment I can't seem to find the courage to call my cousin and to forgive her cuz I haven't forgive myself yet . It's really hard when you don't speak to someone you are close to. It feels I've lost a piece in my heart. It's hurting a lot. I want to forgive but I'm still hurt why is that. I need advice.