Vomiting, fever, and fatigue will be a factor during virtually every chemotherapy treatment for cancer of any kind.
Other than vomiting, these symptoms are often the presenting symptoms of leukemia--the person has an infection, usually respiratory, they just can't shake and they finally go to the doctor. They're running a fever, are really tired, may be coughing blood or having nosebleeds, and think it's all due to some bad cold or maybe pneumonia--until the bloodwork comes back and they tell you to go to the hospital, now.
My husband had leukemia. (He'd gone back to work when that call came.) There are different types, some advancing rapidly, some slowly, some appearing in kids, others mainly in the elderly, or those exposed to certain chemicals. While my husband's leukemia was an aggressive one with a five percent five-year survival rate, he was among the lucky group.
However, once leukemia is diagnosed, great pains are taken to minimize infection, so that part of the scenario you want to write might not work. Leukemia patients can't eat any food which hasn't been cooked, and we had to send back hospital food which had a sprig of parsley on the plate. My husband wore a surgical mask, and anybody who entered his room for any reason had to wear one, too. His clothes and sheets had to be washed in super-hot water to kill any bacteria, and anything I brought from home had to be cleaned with a disinfectant.
The risk of bleeding was taken seriously, too. He wasn't allowed to shave with a razor, only an electric shaver, not allowed to floss, encouraged to be extra careful handing anything sharp, forbidden to eat crunchy foods which might cut his tongue or gums slightly, like that.