I would recommend you to use adjustment layers instead of the direct adjustments (from Image > Adjustment > ...). Thanks to adjustment layers you will be able to redo all the steps no matter if you did them on the beginning or at the end. Set the Input Levels as shown below.

Right click on the Levels adjustment layer and select the option Create Clipping Mask. This way the layer affects only one layer below not all of them. Below it's shown the result of this step. Some parts of the wall are too dark but don't worry about that. They will be covered with another layer.

Step 2 - Bending of the Wall

In this step you will bend the wall. It gives the picture bit claustrophobic feel which will evoke the mood of the picture better. Click on the layer BACKGROUND LAYER. Grab the Marquee Tool (M) and select the left part of the wall. Press Ctrl + C to copy the selection and Ctrl + V to paste it. Then press Ctrl + D to deselect it.