Struggling to Forgive

I can know in my head what God expects from me, but I can still struggle to act, to obey Him.  God tells us to forgive even when the other person does not ask for it and He tells us what the result of unforgiveness is "For if you forgive men when they sin against you, your heavenly Father will also forgive you.  But if you do not forgive men their sins, your Father will not forgive your sins." Matthew 6:14-15

And yet, even knowing this (quite a drastic result), I am still struggling to forgive someone.  I actually wrote about it a few weeks ago.  I had what I call an altercation with this person and I am still struggling to fully hand it over to God.  How to forgive when the other person does not ask to be forgiven? How to forgive when the other person has no interest in even speaking with you? 

I want to forgive, I pray for the ability to forgive, I ask for God's forgiveness for my unforgiving heart, and I struggle.

Lord, help me with this...

In His Grace...