Tumbled in that context appears to be a combination of confused, a little upset and exhausted. It's not a common phrase you'd hear today. Sometimes a finished state is used not to communiate what actually happened but to communicate how one feels if one had actually done that thing.
So if you imagine how you'd feel after 'tumbling' for a while, you'd probably be a little confused, disoriented, maybe a little upset, definitely dizzy, and if you did it for a long time perhaps you'd be hungry too. It's kind of wide open actually.
It's like saying "I was shaken" or "I was deflated". Although they're more common they do not necessarily refer to having had the action happen, but more so to the feeling or visual/emotional association.