Thanks for writing to us with yuor health concern.
I think this is due to perimenopausal changes.
At 51, that is more likely.
OF course, the stress
of the acute gastroenteritis
could contribute, but this is because of perimenopause.
You can easily confirm by ascertaining your current hormone status.
MEasure the following - FSH, LH, Serum estradiol
That will tell you for sure.