Becca,
If you've responded to an E-mail from "eBay" saying that your password needs to be reset, please go directly to ebay.com (do NOT open the E-mail again to get there) and change your password IMMEDIATELY. In all likelihood, the E-mail was a falcified E-mail. Even though the web page you visited may look a lot like a real eBay page (the spoofers are very good!), it probably wasn't eBay.