You've still got one interview left. I know it has to be very hard, but you have to do your best to drop the negativity so you don't carry that energy into the interview. I was in your shoes with one interview as well, so I know it is stressful and I at times felt myself slipping into a similar trap. Head over to SDN interview feedback and try practicing maybe with the example questions. I know a lot of people say don't do this because you will sound rehearsed, but as someone that isn't the most extroverted/people person, having a good idea of what I was going to say helped me a lot. Do your best to think positively though going in, you don't want to create a self fulfilling prophecy and shoot yourself in the foot. Good luck man I'm rooting for you.