The first thing you should do is apply the array modifier and delete the curve modifier from the mesh, in that order. Next, add a new bezier curve and rotate it 90 degrees on the y axis. Then switch to the object data panel for the bezier curve. Under shape, change
Preview U: resolution to 64 (its max).
Then, drag the bottom of the curve over to the bottom of your mesh. This doesn't have to be exact, only pretty close. After that, key
Shift+Ctrl+Alt+C and chose Origin to 3D cursor. Then scale down the curve to the height of the original curve.
Tab into edit mode, and key
A to select all and
W to show a pop-up menu. Select subdivide. Now using vertex snap and your own adjustments, match the new curve to the shape of the old curve. After you are satisfied, delete the old curve.
Lastly, add a curve modifier to your mesh and select the bezier curve. Set the deformation axis to x. Moving your mesh along the z axis will make it follow the curve.
Hope this helps and happy Blending!