I think it's kool that you study mechanical engineering, so that means that you are even kooler than before. Don't give up, don't let the SA get to you. I know it's easier said than done, but you have to do everything it takes to keep going. Sometimes when you feel lost, try to get back to the basics. Think about what is wrong, why it happened, what you can do so that it doesn't happen again and then try to change it.
Skool is hard when you have SA, at least for me. I try to put on a shell, I try to not let my jealousy or inferiority to others get in the way, but my shell breaks every now and then. I get easily depressed and when that happens, I need to escape, mentally. That's when I start staying up late, searching for something that I'll never find, thinking and thinking, then I wake up late, lose many hours to do my homework and study...