You can email Animal Jam about it, they will have a support page:
https://www.animaljam.com/contact !
You should tell your parents, but that may mean they won't let you go on this website. It is probably for the better that you take a break from it. Maybe you could find another game to play for now?
And lastly, most online games have a block function, where you can block people that are harrassing you. You should use this feature on the people bullying you so that they can't contact you anymore!