Why Is Forgiving so Hard?

I posted awhile back on how our forgiveness from God is conditional on our forgiving others.  So forgiveness is really, really important if we want to receive God's forgiveness.

So why is forgiving others sometimes so hard?

Especially when the consequences of the offense are still present.  

Especially when the one who was hurt is one I love deeply.

Especially when the one I love is still hurting.

Especially when the one I love is falling into the sin of anger & bitterness & unkindness as a result of the offense.

Especially when the offender is indifferent to the hurt caused.

How can I teach the one I love how to forgive and overcome bitterness when I am having such a hard time with forgiveness, too? 

I want the offender to have to hurt for hurting the one I love.  I want the offender to not just say sorry, but be sorry, act sorry and try to make up for the offense. I want the offender to receive consequences to the offense instead of the one I love getting all the consequences.

And yet I know God calls me to forgive, truly forgive, fully forgive, regardless of the offender's lack of remorse or empathy or repentance.  

I think this needs to be a matter of lots & lots & lots of prayer on my part. Prayer that God would enable me to forgive and keep that forgiveness in place instead of taking it back when I see more consequences in the one I love. Prayer for the one I love to be healed of the pain caused and healed from the tendency to sin against the offender. Prayer for the offender to truly feel remorse, truly feel empathy, truly repent.