how do i get back?

You don’t need to get back at them. You’ll just be stooping down to their level. Just be confident and know that they needed to do that to build themselves up but you can build yourself up without hurting anyone.

Being popular is not important,they are mean and they have nothing better to do.I will suggest you to be calm first and let other people at school know better about you and who you really are,thats what important right now.Everybody at school will appreciate your kindness and jolly nature and totally ignore what those girls are talking about you.They don’t have any right to say things on facebook,but you can simply ignore them.They are just jealous and the best way to get rid of them is taking things lightly,ignoring them and enjoying with your other two friends.Show her that you don’t care about what she is saying.When she will realize that you are actually happy and the things she say are not affecting you,she will definitely not do that again. I know these types of things upsets people,this thing happened with me too,and the best way i found out was ignoring and enjoying my own life,you will totally forget about them. Lastly,you are thirteen,you should not worry about them and do well in your studies,i am sure your marks will be way better than those girls who have nothing to do but bullying. All the best. :)