Living in your RV for $600 a month

If he has a disease that is considered fatal, he is entitled to disability. Does he have to work until the day he dies? Most times the problem with working is that the employer does not want to let you off work on days you don't feel well, they don't want you having to leave for Dr appointments, sometimes weekly, and to leave again for treatments and repeated tests that are needed MANY employers fire employees when they get sick rather than never knowing when the employee will be able to be at work. Higher paid occupations usually have leaves available or disability benefits that lower paid employees do not have. These type of problems usually occur for the lower paid employees.
What do you do - apply for the disability benefits that were put into place for people in your situation.