I'm older and scared of losing my job. What to do?

You are in your fifties.  Your income from your job plateaued years ago. You have a house full of junk you don't use and don't need, kids growing up, mortgage, bills. You have had an uneasy feeling about your job for some time.  Now, you are almost certain your job is going away, and sooner than you expected.  You know for certain that employers won't pay what you are getting now, and you won't have the flexibility you have enjoyed for the last several years.  The hounds are baying outside your window.  Your options are limited.

This post is for you.  I'm in exactly the same boat.

Forget about ageism.  It's everywhere.  You think it is bad in the workplace, try looking at the devastating effects of age in the dating / marriage marketplace.  Lots of lonely older folks out there.  Ranting and raving about ageism will do you approximately the same good as other folks get out of their particular favorite flavor of identity politics.  In short, not much.  Real people in a position to help you will be put off by it, and will not help.  Don't go there.  No one likes to listen to another person's belly-aching.

Your options are roughly as follows:

1. Do nothing.  Be prepared to accept an old age of regret and poverty.  You will eventually be a greeter at Wal-mart, if you can get a job at all. Drinking will happen.
2. Re-tread.  If you are in high-tech, go into the cloud.  That's one of the few fields where I think new credentialization will be worth it.  If you can become a Cloud Architect or Data Scientist, you will retain a fairly high income, maybe not as high as you are accustomed.  I'm actively pursuing that as one of my options.  This blog, in part, documents that effort.
3. Start a business.  I'm already doing that.  It is a giant pain in the keister, but I'm learning to go fast, even at my age.  The difficulty with this for most people will be the sustained effort required, trial-and-error, lots of failures.  You are not going to even replace your income unless you have a good business idea and you work your butt off.  The only serious caveat with this option is you need income to pay the bills until your business starts paying.  You've gotta have some kind of job.
4. Try sales for a change.  If you are a professional nerd, sales is a great way to transform yourself into a people person.  Those folks do better on average than tech nerds.  You'll still have to work your butt off.

I have ignored such things as crime and terrorism, since they are risky and require physical agility as well as extreme ruthlessness. Most people in their fifties don't have the necessary prerequisites.

You are on the Internet right now. You can survey your options yourself.  Try Googling: "I'm in my 50's and my job is going away! What do I do?" You can ask the "oracle" more specific questions.  Lots of interesting things will pop up.  Survey the territory, and find out where you are wanted and needed.  That should take about a day.

Line up your options.  Understand you have to pay the bills.  Street people are not in a position to start businesses, and welfare recipients will have credibility issues. So, you have to figure out how to get paid long enough to get your personal airplane airborne.  You need a long enough runway. 

Get rid of your junk around the house.  Sell what you can, give the rest away, live lean and mean.  Get rid of all distractions you can.  Focus.  Go fast.  Fail, pick yourself up, fail again, until you get it right.  Many failures will be required before you finally get lucky (it is not really luck, but a system for success).  Die trying.

Get it ?!?