The dr is unsure. But has been thorough. Could it be stress?
Definitely think it is a possibility. I know when I had stress, similar things have happened. And I have also talked to other people that have had similar things related to your situation and they were put on anxiety meds to help and it did help. I am not saying you need anxiety meds, I definitely did not but I think you should manage your stress before it gets worse for sure.
What is your lifestyle like???