Man you have a lot of brushes. I recommend that you divide them up into seperate files then load each file as you need them. Tip: There is nothing stopping you from having the same brush in more than one file.
Is there a way to further divide brush sets into groups? I agree that is an unmanagably long list, and I bet most of them are never used. It looks like Windows 7, so the brushes live in
C:\users\your user name\App Data\Roaming\Adobe\Adobe Photoshop CS6\Presets\brushes\
I've never tried adding a folder to the brushes folder, but even if it is still recognised, I suspect it would not not change the look of that list. I'll have a try though, out of interest.
Here's an idea. Find the above folder, and right click and send to desktop as shortcut, and place another shortcut to a master list of brushes right next to it. Open both, and drag groups of brushes into and out of the brush folder on those rare occassions you need them. Wouldn't it be nice if you could incorperate such a feature into a custom workspace?
[EDIT] Well I just tried, and Photoshop CC sees the contents of sub folders in the Brushes folder. That would help with my weird little idea above, and while my brush list is nothing like the OP's, it is bordering on being too big to be comfortable.