Welcome Denise,
I shared the same concerns as you when I was first diagnosed, living alone and being very independent. What you mention about work, money, and management of bills should be considered as you move forward. When I went through chemo, the social worker mentioned filing SSDI, and taking other measures, just in case, and I laughed to myself saying I'm not doing any of that. Well, I wound up having to do that much sooner, and more.
As far as cancer, that was the easiest part, my doctors took care of that. People, getting what is legally due, and dealing with the things you mentioned proved more difficult, still is, especially when ill.
Not that all situations have the same outcome nor can we predict everything, but everyone should have a plan in mind before treatment starts, more like a plan A, B and C for me, become familiar with your work benefit packages, employee manual, FMLA, short and long term disability, continued payment of bills like through automatic bank payments, transportation, food delivery, food preparation, house cleaning, pet walking, even what your medical and prescription plans cover, do not cover. Some things you may do yourself, have another person, relative or hired help do, and can be changed, modified as you proceed along.
I also suggest to start having your own file with every test, procedure, pathology done. It will clarify things, can save time and money later on, if copies are needed.
Good luck with everything.