I have bulimia or something else?

Hello, people! My name is Lívi, I'm 20 years old and I'm Brazilian, so I apologize for any mistake since I'm writing this with the help of Google translator.

A few months ago I started to notice that my pants fell off my waist. Then I noticed the bones protruding under my skin. So, I decided to weigh myself and found that I was 45k that soon dropped to 42. I never cared about body shapes, but I started to hate mine for the simple fact that I wasn't at neither extreme. I am not skinny. I'm not fat. I'm in the middle of it all. I stopped eating, without realizing it and every time I ate I felt nausea so strong that the only thing that stopped it was to throw up. So, I started to force myself to vomit every time I ate and felt like that.

It was magic. I felt instantly better. Such relief. It was like I took everything bad out of me. Until I start having refluxes. I spend the whole day avoiding eating and when I can't stand being on an empty stomach anymore, I start to eat desperately and after eating, guilt takes over me.

So, every time I feel sad, angry or I just don't want to face my reality, I throw up. I have no one to rely on. I'm alone. And I don't know what else to do. Tonight I was forcing a knife on my wrist, without cutting, just to feel the pressure. I am sure that I will end up forcing myself to vomit today because I am feeling very sad.

Can someone help me to say what is happening to me. Is that bulimia or something else?

After all, thank you for reading this far if you have.