Hi Cindy,
My story is very similar to yours and I'm telling it to give others hope that what can be a very troubling problem can go away on its own.
My fasciculations started abruptly in Oct 2019 - so very close to when yours began. My twitches were quite severe, occurring anywhere on my body at all hours of the day. I too was often kept up at night.
I waited several weeks before consulting a doctor, and as the months went by I saw multiple GPs and had a large number of tests for deficiencies (there were none). I was also put on a muscle relaxant drug. After a year I started charting the severity of the twitches to see if there was a correlation with my monthly cycle or any exercise (there was no correlation).
Eventually after 18 months, I asked a GP to refer me to a neurologist. He sent me for tests to rule out neurological disorders. The tests uncovered nothing new so he diagnosed Benign Fasciculation Syndrome.
A few months later the twitches started to subside very gradually. There were multiple reprisals but they were weaker over time. I didn't believe it at first but it was there in the charts. These days things are good; I still get the odd twitch but it's rare enough for me to consider it "gone".
In terms of the cause: I've been told it might be due to exercise, but I started running in early 2018 and had stopped running months before the fasciculations began. I wasn't running for most of the time that the fasciculations were severe. So I struggle to see how exercise was the cause. I'm running more than ever these days and it's not causing twitches.
I didn't have particularly anxiety-causing events throughout the time either. The only thing I think worth considering is that my iron levels had dropped very low when the twitches were bad, but when my iron was closer to normal, the twitches were better. However, all GPs told me that low iron would not be the cause.
In the entire experience, I found the neurologist the best aspect. He was attentive, explained every test he did, gave me a lot of time in the appointment, described his reasoning based on science and his broad experience treating in the area, and was just a very nice person. Really excellent for a medical specialist!
I hope people reading this have hope that this condition, which can consume a lot of your mental energy, can eventually leave you alone.