Kidney disease and strange behavior. Should I put my dog down?

[mcroft02]

I have a 15/16 year old dog named Peanut. She has been diagnosed with Kidney Disease and our vet put her on special food for her to eat and she enjoys the food pretty well. She was diagnosed a few months ago, but within the last month she has been peeing all over our house. Even though we let her out every 2-3 hours. And today I let her outside, through the back door. She usually just goes and comes right back. We usually don't watch her since she's been trained to stay in our yard. But two minutes later I looked out and didn't see her. I immediately felt regret. I found her a few minutes later up the street, when I saw her running VERY fast, which she doesn't do often... and she growled at me and didn't know who I was. I picked her up carefully and brought her inside, where she began running and bumping straight into walls, chairs, table legs, you name it. She was panting a lot, pacing around. Then about an hour later she laid down and was acting normal again. We just moved to this house about two months ago, but she never left our yard before. Was this something major? Was it just her getting lost and confused? I know I should be seeing a vet but I don't have the money right now. I think it may be time to put her down... but she's been with me since I was a baby. And I don't want her in pain but I struggle with the reality of letting her go.. it is hard to think about putting her down because she still is able to jump and play and she acts like a puppy still sometimes, but sleeps a lot at the other times.. any advice is greatly appreciated and if you have rude comments please keep them to yourself... everyone has been very rude to me for asking online. I just want some opinions.. thank you.

[mcroft02]

Adding to my above post.. she still eats and drinks normal. No throwing up or anything. She acts pretty well and good. Only problem is what happened today and peeing in the house almost every day..