Photoshop won't allow me to modify a .psd I had previously worked on

[clairep91513256]

I am an amateur artist who has been using Photoshop as an art tool for several years; I estimate myself to be proficient in use of the program.  Recently, a problem has come up concerning the use of one of my drawings, where I find myself unable to continue working on it in any significant capacity.

• I cannot draw on any of the layers.
• The color picker tool does not work on any layer, regardless of setting (Current Layer, Current and Below, All Layers, etc).  The color selection ring is only a blank white.
• Auto-select no longer works and I can't move any of the layer, or transform them through the arrow tool or through Edit > Transform.  (The options in Edit > Transform are not grayed out, but they refuse to work once I click on them.) 
• I can hide and unhide layers.  This seems to be about the only thing I can do.
• This is what the right-click menu for layers looks like (note that this was on an unlocked layer):
  
• This is what the Image > Adjustments menu looks like:
  
• In the above Image > Adjustments menu, the options that are not grayed out still have absolutely no effect once I click on them - the box pops up, but no matter how far I push the sliders the layer itself doesn't change.
• Most frustratingly of all, when I try to copy-paste each layer into a new .psd so that I can keep working from there, what ends up pasting is only a blank white layer the size and shape of the canvas.

This is the only instance of this problem I've seen - none of my other Photoshop files have or have had this problem, including ones I've created and worked on since this one, or ones that I have open at the same time as this one.  Additionally, neither restarting Photoshop nor restarting the computer seems to help (I've been opening this file intermittently every few days to fiddle around with various tools and see if anything works, and in the intervals between there has been plenty of computer restarting and Photoshop restarting), and I haven't gotten a single error message or unusual dialogue box this entire time.  This leads me to believe that the problem is with the file itself.  The only thing I can think that I've done differently from my other drawings is using more adjustment layers than usual.

I was really happy with the direction this drawing was going and would hate to have to abandon it.  Does anyone know what in the world is going on, and what I might do to fix the problem?

[Silkrooster]

Could you capture your entire screen with the layers panel open and any collapsed layers, expanded so we can see them?

[clairep91513256]

Blurred out the image because I'd feel silly showing my art of cartoon robots on a serious forum (still in the sketch phase, hence the rather uniform image) but here it is.

(Not sure what you mean by collapsed layers, meaning I probably don't have any if I don't know what they are)

[Silkrooster]

Ok, take a look at the tab at the top of your canvas. It says quick mask. You need to hit the q key to get out of quick mask. Then all the options should be available. If not let us know.

As for collapsed layers, there are several ways this happens. Adding any styles to a layer, will auto hide the styles used.

If you group the layers, the group it self can be collapsed, hence hiding the layers.

Moving the top of the panel down will hide any layer that won't fit in the space.

Technically collapsed is not a good term as in this case has several meaning, but is generally the quickest way to respond. I apologize for any confusion.