I think the only way to be more confident about it is to enhance your other features. Disregard your own flaws and focus on what looks good and make those features stand out. And remember that people can only love you as much as you love yourself. When you stop worrying about your overbite, you will attract other people who also don't care about it.
If it makes you feel better I have huge teeth (like Alyssa Milano) and a small mouth with thin lips. It's a terrible combination because my small mouth make my teeth look even bigger. When I smile I purposely cover the bottom half of my "horse teeth" with my bottom lip so they don't look so huge.
Go back to your orthodontist. He or she must not have finished the job.
Get better insurance or start saving your money.
Do you live in the USA?
I assume you're not covered under your parent's insurance.
I had it done for my under-bite and it was covered by my parents' insurance when I was college age.
That was over 30 years ago Honey. I have no idea. Check with your parents' insurance company and find out if they'll pay for it.
Just know that everyone has "imperfections", some are more obvious than others. I personally would rather have an overbite, as opposed to being born a psychopath.