Anger spoils a lot of good things, anger makes someone to make a lot of mistakes which the person regrets after the anger subsides. And unforgiveness means you are also restricting and tying yourself down, because you won't be free and won't be at peace, while the person you refused to forgive is comfortable without knowing that you are dying inside, because of the kind of anger you have in your heart towards him, so therefore when you have refused to forgive you are tying yourself down and also killing yourself inside.
Don't be angry when someone has done something wrong to you, I know this is impossible for some people because, human nature and human instinct dictates that if somebody does something wrong to you, the only thing you are going to do for others is to get angry and react. for any action there is always an opposite reaction. Of course yes there is an opposite reaction, when someone does something to you the reaction of a Christian is not anger. You must replace it with happiness. If somebody sinned against you it's an opportunity given to you by God to forgive.
This is indeed an eye opener to us towards anger.
REMAIN BLESSED!