You probably are having a doosy of a UTI...
I am not trying to offend you, but did you have sexual relations on Saturday perhaps?
After menopause the vaginal area and canal lose elasticity and moisture so sometimes relations can result in microscopic tears. Just a thought.
Ofcourse we all self medicate when we shouldn't but I thought that I would just tell you that certain antibiotics treat certain problems, kind of lock and key...ya know? Amoxicillian isn't used to treat UTI's, it is mostly used for respiratory, ears, nose and stuff. Just an FYI.

I think that going to your PCP tomorrow is a good idea, just to do a UA. Make sure that they culture it!
I hope that I helped in someway.
Have a goodnight!