Terminal cancer - husband has been given a maximum of 3 years. He doesn't want to accept help from others. How hard will this become?

My husband has been diagnosed with terminal cancer of the kidney, lung and now showing signs around the heart. He has been given a maximum of 3 years. We have told the family, he doesn't want to accept help from others but I'm worried as I still need to work full time on a stressful role. Can anyone advise as to how hard this will become.,the only treatment can be a daily tablet to slow it down.