Meaningless bullying on my story?

So I decided to go on FIMFiction to check if anypony commented on my story... I was met with several rude and hurtful comments and someone posted a video saying 'Retard Alert' ... Wow so hurtful that I'm actually crying. This is the 2nd brony site I have been bullied on. I get it if somepony doesn't like my story but there is no need to go and post such mean things on it. Constructive criticism is one thing bullying is another and it's not ok. My story is not finished yet so it's not perfect I get that but to just be so rude about it... I'm really upset now.