Lisa, you were on the correct trail. All you do is always keep the canal (both the spur you first saw, then later the main canal) on your left. The pathway finally comes out up by House of Blues and Cirque du Solei. Outside of the 'bridge' you first crossed by bldg 55, do not cross any other bridges
Eventually when SSR opens, you will be able to cross the bridge that went to the old DI, go through SSR, and come out close to the other side of DD, over by the Rainforest Cafe end.