Do you think it's bad if I start an argument with a friend?
It could be, why do you want to argue with him?
He hurt my feelings last week and he doesn't seem to understand that.
Sometimes friends get into arguments but you should find a different way to resolve your issues. Tell your friend how you feel because he may not understand how he hurt your feelings.
I'll try, I'm not sure that he'll understand why I'm upset.
You should still talk to him and make it very clear how he hurt you. He should know what he did so that he doesn't hurt your feelings again.