Putting my hamster down

I have to put my hamster down tomorrow 😔 she’s a winter white dwarf hamster and only a year old. A couple months ago I noticed a growth by her leg so I took her to the vet and it turns out that it was a tumor. We considered getting it removed but that was going to cost over $500 and we just can’t afford that. I decided to let her live out the rest of her days in her big cage but unfortunately it has grown to the size of a golf ball with multiple scabs on it. She was still acting normal till about a week ago she stopped running and going in her tubes, I notice that she’s also biting at it when she’s awake. It is the most pitiful thing I’ve ever seen and I just can’t let her continue to suffer. My heartbreaks for her but it’s the right thing to do. 💔