Well that's the first step; letting it out! Thank you for letting us know how you're feeling. You are an important, helpful member here.
Try to find something, anything that you can do about your current situation. Pick one problem at a time and do something, anything to gain at least a little control over it. It's also possible that your "employer" is more negative than most and should be avoided if possible. Long walks and physical tasks can pull you out of your head and onto your environment.
Try the above, keep posting, and let us know how it's going.
Keith