Stuttering in front of the whole class.

Stuttering in front of the whole class. Hi, I am a Swedish student with rather good grades. School has always been my number one priority and I excel at a lot of subjects. A couple of days ago in English class something happened that I am still thinking about. I have been having blocks for a long time and they have been really stopping me from showing my full potential. Because Oral presentations stand for a rather large part of your grade here wher I live (and you have them in most subjects) I feel like my grades don’t do my knowledge and abilities justice. I can talk, I can pronounce everything correctly but it just won’t come out of my mouth. So let’s get back to what happened a couple days ago. We were writing essays in English class and the teacher asks us to stop because she wanted to show us some student examples that we had to grade. So we all finish and then she asks us to give feedback for each Essay. She shows this essay with a really bad structure and a bad hook in the beginning. I raise my hand and she picks me. I start talking: ”The structure of the text is p...” I was meaning to say that the structure of the text is pretty bad but the word ”pretty” just wouldn’t Come out. I sat there for what felt like at least thirty seconds (probably ten in reality) trying to get the word out. Everyone were staring at me and all you could hear was ”p...p...p...p...p”. Finally the tacher says. ”Yes the structure of the text was pretty good.” The structure was actually terrible and she had just said that to end my misery. I felt so humiliated for some reason. I felt like the time was up. I tried to say something but everyone ran out of patience so someone had to generate a word that might have fit in to my sentence. For the rest of the lesson I sank in to my seat and shut up. Since that day I barely ever raise my hand in class again. Please give me some advice these blocks are really killing me and my grades, not to mention it has destroyed my self esteem.