I have been in anxiety-provoking situations without the trembling —- for example ignored for 15 hours overnight in Emergency waiting to see someone as directed by my doctor’s office because he was too busy to see me. No help!
It is erratic, always in late afternoon or early evening. I have associated it with spikes in ordinarily normal blood pressure.
The situations surrounding these events have never involved anxiety. BUT I agree that having had Covid facilitates my trembling events, something the Emergency doctor dismissed immediately though like you it’s onset was triggered by Covid.
I already take Lyrica because of pain in neck and shoulders related to spinal damage relating to lifetime injuries.
For sure, these events cause some degree of anxiety. I seek to find a way to stop them, and am currently looking for a trigger that causes my blood pressure to precipitously drop.
I suggest that perhaps your “anxiety” is an “anticipatory response” to a terrifying body reaction., triggered by your now being more reactive due to Covid.As you say, you were not an anxious person before, and you are still that person.
I suggest taking your blood pressure during these events. If it drops, as mine does, then look for reasons why this is happening, for “associated variables.”
This is where I am at now.
Thank you for your very careful and detailed response to my post.

are your symptoms made worse by food?
if so, what diet changes have you made?
thanks