There is no such thing as start over or fresh start. This isn't a video game, this is life. You can only continue using with what you have redeeming your mistakes or simply log out and never come back. That being said, it is not like you don't have any other options than quitting. There are multiple ones.
1: Download Freeleech and let it on seed until you get your downloading rights back.
2: Become a VIP and instantly regain your rights.
3: Come back on international festival season like christmas to make use of the option of freeleech for all, to download anything you want even if you are below the minimum ratio and let it seed to increase your seedbonus which you can use to buy upload credits which will increase your ratio.
Personally, i would tell you to become a VIP and give the community a chance to grow. Since the community has already given you 12GB worth of data, it is only right that you give back something to the community which you have taken advantage of without giving anything in return for the past 4 years.