The vet told me that his infection has still not gone away.
Do they know for certain that the infection is still there?
I could barely pet him the other day, the poor thing is sad.
It's good that you took for sick pet to the vet. It can be heartbreaking to watch a pet suffer, but you should listen to the vet's advice about treatment, even if that means accepting that the infection can't be cured. You are doing everything you can by taking the pet to the vet so don't feel too bad about it.
I wish there was something I could do. But he keeps refusing to treatment.
Maybe you should visit a different vet because there might be other forms of treatment methods. It never hurts to get a second opinion, especially when it seems to be life-threatening. At the end of the day, you can only do what you can.