You can do this.
Internalize those words and you're good to go.
Confidence is tough. It lacks where it shouldn't and shows up in the places you need it the least. It can drive you crazy at night with thoughts of "if only" and "I should have done this differently." The hardest part about having confidence? You have to make it; you are responsible for making it show up where you need it because as great as it would be, there isn't a magical fairy to shower you with confidence dust when you go to present a project in front of your class.
I feel as though the biggest inhibitor of confidence comes from a mindset where you doubt yourself. If you tell yourself you can't do something, there's a good chance it's not going to happen. So here's what I do: when I feel like there's no way I'm going to be able to do something, whether it's interviewing a popular guy for yearbook or auditioning for a clarinet solo in band, I just try to let go. By that, I mean I try to forget about everything that could cause me to get nervous and lack confidence. I just stop worrying.
It sounds simpler than it is. But, take a step back in your mind and think about living in the moment and not worrying about what will happen before, during, or after. Just plunge yourself into it and you'll find yourself doing something you never could have imagined. Talk about a confidence booster!
Next time you feel like you can't possibly be confident enough to do something, think to yourself, "I can do this," and just go for it!