Do you have a save before entering the Hall of Echoes (other than the one 3 levels back)? You may be able to upgrade your enchantments, add charms, possibly adjust your skills, etc, even if there isn't anything left to do in order to get another level. From the dragon sections of the hall you can return to the battle tower, but not leave there to go anywhere else (which may be good enough).
If you do end up reverting to your level 30 save (it shouldn't be impossible on level 33, though), there are a couple places where you can get opponents to spawn, if you have not finished off those sections yet (
how to reach level 40+).
FWIW, the upcoming patch (expected around the release of FoV/DKS) is going to adjust the level dependence of combat.
