The Ribbon is comprised of Tabs and Panels.
If there are any menus they would be the "old" drop-down or pull-down menus like File, Eidt, View, Insert, Format, Tools, Draw, Dimension, Modify, Window, Help and Express.
So you lost both of these features and the QAT as well?
Have you tried the CUILOAD command?
How much customization of the original acad.cui had you done before you shot yourself in the foot?