Scared in Public. Getting good grades.

I am having these issues in facing people. Since now I am doing engineering , it is important for me to make friends and be good at public interviews. But I constantly fail at it. Ex. I start speaking after being motivated and stop in middle and get fearful. I don't even  have Facebook account since I was an introvert from school only and I dropped for one year to prepare for iit but eventually failed and now is in a local hometown college . This made me not to be on social media mote since I have to face so many questions. I lie also and I don't have any best friends because of that. People become my friends but I don't know how to not act in front of them and be real and the ones I was honest be I afterwards realised are not even my good friends .As my years in college are going by I am getting more and more depressed and I am not even getting good grades.