There is a guy who I can't forgive.
Is there a reason you haven't forgiven him?
No, and even after you ask, I still can't forgive him
It's okay if you are angry at someone for what they did to you, but in the long run, it is better to forgive and forget.  Let him know that he has caused you pain, but don't let it keep eating away at you.
I want him to feel my pain.
I totally get wanting a person to feel what you went through, but forgiving and forgetting is better for you. Moving on matters and you don't need to be stuck in that moment and experience.