On one hand you say she is fine when she is free and you are not there but on the other you say she freaks out even if you play some form of hide and seek with her and she can't see you. I'm not sure I followed the three doors being replaced... was it because she scratched them up?

I do believe what you described is seperation anxiety. Your best form of treatment is to find a veteraniary behaviorist in your area to work with you on this problem one on one. Your vet may also prescribe mild sedatives to calm Misty if the problem is really severe. In the mean time, try to find something that Misty likes to distract her attention from you being gone. For Dixie it was giving her Cube busters filled with treats she had to work on to get the treat out. By the time she lost interest in it, I was long gone and she was ok.

It's not an easy task to deal with a seperation anxiety filled dog but it can be done. You just need to figure out some calming stratagies and behavior modification plans. I suggest a behaviorist to help because this is not a one cure solution for all dogs. What works for one dog doesn't work for another. A behaviorist will be able to analyze you and Misty and perhaps "see" what will work to help.