in the folders on my computer. If I open the html files from the folders they open with all the work I've done but when I try to open the VNU file in coffee cup it opens the vnu file but all my work is missing except the first one or two things I did....
I don't want to have to redo all the work I've done and there must be a way to get it to open with all the work I've done especially if all the html files open as such.

Can someone help?

If you've edited the html files you are not able to go back to VSD and do it now. VSD and HTML editors don't work together it's a one or the other type situation. I know this ain't what you wanna hear, but unfortunately they are entirely different file types. Once you use VSD you need to either stick with VSD or use the HTML Editor from the point you start editing them in HTML