Yes, I am glad you got back in touch with me. There was a time in my own life, too, that I considered close acquaintances friends of mine, but I soon learned (though not soon enough in some cases), to separate the two.
You cannot expect loyalty from colleagues. Some, yes. Most, no. Sure, there's a spirit of familiarity, sometimes you socialize with them, maybe go out for a drink after work, or maybe you get together every Thursday for a game of competitive volleyball. In these times, you can get an appreciation for their home life, or share some giggles, even commiserate about this year's puny salary increases, but there's no mistaking that these folks are not your friends. I am so sorry to hear that you got burned by obviously bitter (aggrieved? resentful?) former colleagues. They must live a miserable existence if they believed that bad-mouthing you to the new head honcho would secure their jobs.
Do you really think that they have (had?) that much power to get you fired?
I know that you were "restructured" or "right-sized" or "downsized" but it still feels like being fired, doesn't it?
You sound as if you are experiencing typical mix of emotions that comes with losing your position. You've lost your position in the world, your career trajectory has been interrupted, and it's overwhelming to think about the challenge of finding work.
Maybe you ought to take some time, allow the experience of anger and resentment wash over you. Let the tidal wave of emotion wash over you. But don't let it drown your sensibility.
Because if you are anything as brave and persuasive as I recall, you'll have dozens of job offers before you know it.