Treebo, I've had plenty of days like that. You just want to sit and stare. But, what I do is I pick something to do and get busy and then those feelings go away. Just the moving and accomplishing things helps with those "blah" moods. If you are to work today, then get ready to go! You will be fine. Many times I end up having a good day after a lousy beginning like this.
Also, don't tell yourself you "can't" do something. In most cases, you really can do it but you are convincing yourself that you can't. That's some depression speaking to you. You don't want to live your life like that. So, choose what is important for you to do and move forward. I hope you have a happily surprising day today!
Sherrine