Max's Fight: Help with His Injuries

I found Max when he was little kitten when I was very young. He is loving, caring, and friendly ever since I had him as an outside pet, but he has gotten arm infections on both of his arms for a year now. I do not have the funds for his injury and many more vet medications he needs. He is growing older and I want him to stay inside now because of his age. There are a lot of cats in my neighborhood so, he often fights many male cats to keep his dominance. However, he is growing weak and getting more injured in the process. Please help, every dollar will matter for him.