I am so sorry to hear this about your boy.
My Coleman had a mass coming off his spleen - the doctors wanted us to do chemo which would give him maybe 6 months to a year depending. It would have meant driving him 2 hours one way for is initial treatment a couple times a week. We opted not to do chemo - kept our boy home with us and managed his pain level. We had Coleman for seven more months he passed 4 months before his 11th birthday.
All I can say is keep do what you are doing it is all about the quality of life.