Help Scamp go to the Vet

Hi everyone. So here is my situation. My Scamp is almost a year and a half. Lately he has been going potty every 5-20 minutes. He also goes potty every time he gets even a little excited or afraid. He’s been whiny thirsty and not really playful. I’m worried something could be wrong and I want to take him to the vet. I am not working due to numerous health issues so I cannot afford to take him in. I’m sure they are going to want to do tests and charge for the visit witch is why I’m asking for $200. It should be enough to cover. Any donations will be very appreciated.