Thank you for reaching out to the Community! I apologize that you have had this experience. Can you give us some more information about how it is slow and where?
What browser are you working in? Are you having this same experience through a different browser or a private/incognito window? We have seen cases where 3rd party add-ons could affect how Constant Contact works in a browser. So testing your browser like this is always the first troubleshooting step we suggest.