I experienced the exact same a little over a year ago. If the whole program is formatted this way the you will just have to put aside a weekend where you don't write code and just format.

I setup a keyboard shortcut to join lines using Options-Environment->Keyboard. I set it to Ctrl+J, Ctrl+P. This only works across two methods.

Start your selection below the first curly brace that appears after the first method signature. Select over the next method and end your selection before the end curly brace of the second method as shown below

Use your shortcut to join lines. it will appear as below

Apply the Ctrl+K, Ctrl+D key combination. The outcome of this is shown below