You don’t need to buy a new account; just use your old one. You simply need to wait out the 2 week ban on your original LFS account, and then start acting mature in all aspects of his life. It doesn’t harm anyone if you start acting mature.
As for the bans on various servers; once you start acting mature from now on, you can simply give the server administrators a personal message on the forums or a mail message and request to be un-banned, giving various reasons why you should be un-banned. This may not get you un-banned on all servers, but when some server administrators see that you are acting mature and admitting to your mistakes, they may have a change or heart and UN ban you. This may not happen in all cases, but it’s certainly worth the try.