Braces vs Invisilign?

I am 18 years old and just graduated from high school. I got my braces on about a 15 month ago. Ever since getting them on my confidence has dropped and I often feel almost depressed. I understand that a lot of people have braces, but I already have some confidence issues and really, its only myself that I care about. My dentist promised that if i didn't have them off by my prom and graduation that he would take them off for the occasions. Finally prom came around and he was not happy, but he took them off anyway. He left on the anchors in the back and the pallet expander that I recently got. The thing is, is that I do not want my braces back on. No one understands how ugly they make me feel. After getting them of I started noticing that when I laughed or smiled I would instinctively cover my mouth. I have been wanting to switch to invisilign for a while now. I am only half way done with the process but I do not want braces in college. My teeth are straight, its just my overbite. My mothers insurance has already covered braces once, so I don' no what I can do. I honestly hate my life with metal in my mouth, and the pain is sometimes unbearable. I just need an alternative. Does anyone no how much this treatment might cost? Ideas for payment? How to help my parents understand? I thought I could use some graduation money to help!