I think it's easy to be angry at a person you've forgiven especially when they continue to hurt you or offend you.
I don't know the answer to your question, but I had to say I often wonder the same thing: if I have forgiven someone, does that mean I should feel no anger anymore, at all?
Or does it mean I haven't truly forgiven them?
I have had to set some boundaries for people who continue to harm me, and I distance myself as much as humanly possible from them.
The reason why you feel this way, is because when you forgive a person you are to love them as well, after all HE said to forgive and love one another.
If you still feel anger toward that person after confessing and repenting your sin of anger, and after forgiving them, then you haven't really assessed what forgiveness is all about.
You can run away from those who are sent to test you in patience, self-control, faithfulness, gentleness, goodness and kindness.
HE keeps on testing me as only the other day I had to endure continual belittling and insulting remarks by two blokes who inferred they were doing it in fun, but they were getting personal. After much over the past few months, and then the other day they had taken it too far, and I gave them a blast and basically told them to grow up and mind their own business. Now they were offended of my outburt, and then tried to turn it all around as if they didn't do anything.
So on my way home I was angry, really angry, then I became angry with myself for letting them take advantage of me, when I should have just ignored them. But, I wasn't feeling the best and they had taken it too far, and I was weak.
When I got home, I then took it to our Lord Jesus Christ and confessed and repented my anger toward them and toward myself. I forgave them and myself, and ask our Lord to forgive me.
Now I have confirmed that I love them. But, I have asked myself do I go and say to them that I was sorry for giving them a blast. NO, but I will not avoid them, but be right back in their face as if nothing had happened. Turn the other cheek for them to strike again.
Love is the answer to forgiveness, because it NEVER FAILS.
Be blessed in Jesus' Name.