Dog with Squamous Cell Digit Cancer Help :(

Hi I am new and have been on all day researching for my 10 yr old rotti Diesel. He was diagnosed in August with Digit Squamous Cell Cancer. We had the toe removed and even with the lab saying the margins were clean, it has come back worse then before. The vet wants to remove his leg, but he has been through so much and I don't want to do that with fear it will come back worse. I was reading about Inositol/IP6 and Colloidal Silver and was thinking of trying that. He is currently on Antibiotics , pain killers and artemisinin but it just keeps getting worse. Can anyone please recommend anything or share anything that can help my baby. Thank you so much <3