I feel the same - dreading to come to work because it has become the most depressing place (WM HO) I have ever been employed. It's like zombie-land at the HO. All our current directives - automating and abend prevention - means we are making our jobs obsolete or outsourced.
NOTE: Abend aka Abnormal End. The unexpected failure of a piece of computer software.
It's all a game of Russian Roulette. Eventually your time will come and they kick you to the curb.
I want to leave also but I ask advice of my friends. They tell me to hang on. I get paid decent enough that I can save for retirement here. I'll milk that for as long as I can, take the severance and find a new job when my time comes. A even better one. One where I feel like a valued member of the team. One where the stress is nonexistent or minimal. One where I am a name and not just another drone doing my job.
In the meantime, hang in there. Take training and develop new skills. Keep your resume updated and posted. (I get up to a dozen e-mails a day for jobs around the country.) Save your money because more than likely you will have to pay your own way to relocate. Declutter your home in case you have to relocate. Make sure you spend time outside work doing those things you really enjoy. Meditate! Exercise to burn off that stress. Finally, keep your options open in case you have to go back to school for a career change.
As an aside, and before WM, I had a friend at another company that was treated like crap. He moped around his house outside of work. His wife finally asked him, money and any excuses notwithstanding, what would you do for the rest of your life? He thought about it. He said being a truck driver. His reason? He was sick and tired dealing with stupid people in the corporate world. He had a CDL so he became a local school bus driver to refresh his license. He then went to truck driving school, passed and became a cross country driver.