My “Friend” keeps pointing out that I have big boobs and she calls me fat sometimes. She also got mad at me for talking to my other friend about this, How do I get her to stop?

Your friend pointing out your breast size and weight sounds difficult for you to deal with. If it makes you uncomfortable it is unacceptable for her to do this as well as if it offends you etc... You have every right to talk to your other friend about this if it makes you feel happier or whatever and she has no right to get mad at you especially when she's the one in the wrong. To get her to stop I think it is important that you talk to her about it and how it makes you feel, if she continues then talking to an adult about it may improve the situation and then go from there.

Perhaps she's jealous! First of all be proud of who you are. Know that it's ok to tell her what you need from her as your friend. Ask her why she thinks it's ok to make negative comments about your appearance? Tell her that when she says things like that it is hurtful and you would like her to stop. Hopefully when you explain to her that you don't appreciate her behavior she will listen. Unfortunately, we can't control other people and their actions, so she may decide not to listen to your request and continue with her disparaging comments. You do however have control over your own actions, and if she continues, you can decide whether you really need someone who does not respect your boundaries as a friend.

Explain to your friend that this is hurting your feelings and that it’s extremely insensitive of her to criticise you in such a critical manner without trying to put your feelings into consideration. She should not make you feel guilty about wanting to talk about this situation to another friend of yours and you need to explain to her that you have the right to confide in whoever you want and that if she does not change her toxic behaviour then you would not be close to her anymore since the friendship is hurting you and is unhealthy as well.