Can't afford treatment for my dog.?

I noticed a growth on my dogs the other day while giving him a bath. Its something that his tail and fur covered up but he lifted his tail while I was giving him a bath and I saw it. I called the vet and they said it might be something, but when I took him to the vet I found out that it was a tumor. Its rather i guess large and I think it makes it hard for him to use the bathroom. The surgery is 1000$ and I cannot afford it and even if I could they won't know until a bit after whether its a permanent fix. As of right now he seems to be normal but I don't know what to do. He doesn't seem to be in any pain at the moment but I don't know for sure. I know it has to make it uncomfortable for him to use the restroom, but again I cannot afford treatment. One of the main issues is that the tumor is I guess for a lack of a better term, leaking and it seems like a bloody messy discharge. I mean its not like dripping or anything, or like a faucet of bodily discharge but yeah its leaving like stains on his bed and stuff. So my I was considering Euthanizing him because he is 11 years old and because while he isn't in pain now I don't want to wait till he starts showing signs of pain to put him to sleep. I don't know what to do and I understand that asking random people might not help but I need to know is it wrong to want to keep him alive because I don't wanna lose him? Or by the same token is it wrong to euthanize a dog who isn't showing signs of pain but has a tumor impeding his bodily functions? I love my dog very much and he has been a great friend and pet and I don't wanna lose him, but the tumor is pretty bad and like I said he is bleeding/discharging some sort of fluid that isn't getting everywhere like a mess but is staining his blanket. I am not sure what to do :(