Yes, you can close it and start a new one with the same email account.
You sure? OP is a premium member; I'd hate to see him lose his diamond privileges? I know regular members do it well, regularly, but multiple accounts are a big no-no in the TOS (that legal thing no one ever reads?).
Not really a big advantage to starting over. Your Glicko RD will be so high after 4 years, it will almost be like starting over anyway. IMHO.
I didn't play on Chess.com for about 4 years and then recently restarted. I realized that my account shows stats of a flat line for all those years. Is it possible to close my account and then just restart it, so that the stats and my information will all begin anew? Can I use the same email account?