This may or may not help... it's certainly something that works with many if not most UK ISPs, but I have no idea what the situation is in the USA.

Here in the UK many (if not most) ISPs will NOT automatically disable a customer's mailbox if that customer stops buying their connectivity (broadband or dial-up) from them. Instead the mailbox stays open and continues to accept mail... until it eventually goes over-quota and starts rejecting mail with a "mailbox full" message.

In most cases (i.e., unless the ISP has blocked remote access) ex-customers can continue to pick up mail from their ex-ISP's mailbox (thus stopping it from going over-quota), by either setting up their mail client (Thunderbird, Outlook, whatever) to collect mail from their old mailbox, or by using a generic webmail client such as www.mailreader.com.

This definitely works with the majority of UK ISPs... it may or may not work in the USA. If it does it would solve the OP's immediate problem... though long-term the best solution would be to aquire a permanent email address by either registering a domain or going for a forwarding or webmail service such as Yahoo or Gmail.