I was playing vollyball in gym class?

Lmao. No. It happens to you when you first start playing volleyball. Yes, it's painful, but your arms have to adjust to hitting the ball. It should stop within a week if you continue playing. :)

Dont worry its nort permanent.

It happen because you are new to the game and have learn the correct way to play it yet. Its not permanent! Once you learn how to use your hands the right way. You will learn how to bump, sets,dig

and hit the ball with your hands.

It's not permanent, it'll eventually go away. It may hurt a while when you're new to volleyball, you'll get used to it if you play more volleyball a lot of times. Also if you like wearing bracelets, watches etc., I suggest you not to wear them when playing volleyball, because the impact that the ball is coming to your arms are really hard and also it will hit your bracelets and gives you even more red marks on your skin, also it hurts a lot if you wear your bracelets while playing volleyball. Remember to take out your bracelets when playing volleyball, and other sports that's mainly use of hand contacts.

Good luck, and have fun! (: