Relax, young man.
i can understand your DM is bad, he pick on you, punish you without
a very valid reason.
But think on the positive side, this is a good lesson to you. Look
further in your future.......
You may have an evil boss that pick on you even worse.
You may have cunning collegue who backstab you.
You may be treated even more unfair than this.
You may feel that you live in a society that lack of freedom in
other area beside "freedom to choose run or walk", and those area
affect your life more.
You dont have to thank him, but he already somehow help you to get
use to this world.