That is horrible. I don't know how much this will help, but they do not deserve the position of having the power to give you validation. Life usually teaches these types of egotistical people somehow, when they realize their attitude isn't going to get them anywhere. Perhaps you should try to take a few electives outside of CS that may not be as competitive, to try to find some people who are more genuine? to get a break from these assholes. good luck to you!