This sounds too familiar. Reggie is 12 and will be 13 in march too...he's having the same problems, frequent urination (we have to keep a diaper/male dog wrap on him in the house all the time now), drinking lots of water, shaking, he had some bald spots a while ago too but that went away...has plenty of apetite though. My mom took him to the vet a few months ago and they did tests and didn't find anything wrong, though recently the urinating is getting worse so I've been bugging her to take him back again. I hope everything will be ok with Lily!