Awww girl - I know how frustrating it is. And not easy with kids. And your ex is a narcissistic idiot.
Maybe once the pandemic is over, you can get a trusted girlfriend to vet your online picks for you? You don't seem to have a well-tuned antennae for weeding out the chaff. Or you can get involved in some groups that might lead to meeting single guys naturally.
And in the meantime - other relationships can fill some of those voids. My BFF fills a lot of the "sounding board" role that a spouse used to fill. Friends provide companionship. Put more effort into those relationships.
Take the focus off of dating for the present. It's too hard in a pandemic anyway. (Although you can screen future dates by asking them whether they wore a mask in the pandemic. All the Covid deniers you can eliminate in one fell swoop).
Sorry too about the job insecurity. It's a tough time to be putting feelers out, right before Xmas, but might be a good idea to start networking a bit at least. And figuring out how best to make yourself indispensible at work if you prefer to stay after the acquisition.
It's just a lot. I get it. And you are in the thick of it with your kids right now with an ex who is useless.
Let me just tell you, you are NOT nearing any kind of end of your attractiveness. I only started dating again in my early 50's after my divorce and it was NOT a problem.