I'm mad at that girl for not thanking me for my efforts
Are you really that mad about it?
Yes of course I am. Does she have to be so rude?
When you do things for people it should be out of the goodness of your heart and not for glory. Maybe this girl didn't get the chance to thank you, or she didn't realize that you had put in the effort. You should just appreciate that you did something good and get some joy out of that.
It's alright, I don't care about a lot of joy in life.
It's okay if you don't want to feel joy in your life, but holding onto grudges like this will cause you more pain than it is worth.  It was very generous of you to help this girl in the first place, and I'm sure you felt a lot of satisfaction while you were doing it, up until the point that she didn't thank you.  Just remember how good it felt, and use that feeling for motivation.