Why would you lose everything? The advice was to move your files over and take all the time necessary to make sure you have everything before deleting the old account "eventually."
If you didn't delete the old account yet then google how to transfer your specific mail program and it will tell you what file it's stored in and how to move it. If you can't find it tell us your mail program and we'll find out for you how to move the mail, settings, bookmarks, etc. Most people use webmail which is stored on the service's site, so this is not necessary.
IE has condensed all of the controls into the Gear icon on the top right, but if you want the Menu bar just rightclick on a blank area of that same bar and choose it, or try the Command Bar which is similar.
Under Tools (or the Gear icon) choose Internet Options to set your Home page on the General tab, Favorites will show up on Menu or Command bars. To populate your Favorites copy them into the new User accounts Favorites folder.
It would have been nice if you'd even told us if your issue is solved before getting hysterical about the "Compete mess" we caused you. We fix these issues here every day. There is nothing we can't fix, which is why this is the top tech forums on the web.