This should help you locate the library, and further troubleshoot the document upload.
If those steps don't work, try uploading in a different browser or a private/incognito window.
Sometimes trying another browser helps! Especially if there's possibly any third party add ons preventing a specific action in your account.
If you require any further help, you can always reach out to use at email@example.com, and we would be happy to assist!
I'm sorry to hear you're having this experience! Are you looking for a full document or an image of your document? Are you unable to see your images in your email editor or in the Library itself? A full document can only be seen in your email editor through a document link. So having these clarifying details are helpful to help troubleshoot this further for you. I have taken a look at your account and was unable to replicate this same experience. I can also see your newest image does have images added into it. Are you still in need of assistance? If so, whitelisting Constant Contact is always a great first step.