Learned some new vocabulary and tried to use it in context. Please spot and correct errors

This is a paragraph which I have written to use some newly learnt vocabulary words. I have made all the learnt words bold. Kindly check for mistakes.

Sam was talking incessantly in the Physics class. He was ranting about the vicarious thrill that he gets by playing violent games in the smartphone. Listening to him, I realized, these games are the reason why Sam rationalizes his violent and aggressive behavior. I am his close friend and well aware about the gregariousness of my friend. But his constant chatter was becoming intolerable for the professor. Suddenly, the professor pointed out my friend with his finger and asked him to stand up. Then he started a diatribe against my friend. At that point of time, one of the most obsequious students of our class complained about the violent behavior of Sam. I could easily sense the obsequiousness from his way of talking. It was not at all the right time to complain about Sam's behavior. Sam became maudlin in the class and I could literally see tears in his eyes. I think this was a turning point of Sam's life. After this lecture, we both sat together and discussed his problem. I advised Sam that he needs to sublimate his aggression into something creative.

Next day he did something amazing. He wrote "Sorry Classmates" on the blackboard to expiate his mistakes. Everybody knew it was written by Sam and they came to him turn by turn to console. I was really proud of my friend. Even the obsequious guy who imputed Sam for violent behavior said sorry to him. I remember vividly that Sam was hesitant to attend the Physics lecture because of last day's incident and I was importuning him to attend the lecture and face the teacher. My efforts did not go in vain and he attended the lecture. This time sitting silently and attentive in the class. That year Sam scored the maximum CGP in class.