Work Accommodation battle - any tips or advice?

 I have been stable but recently has had to deal with a lot of stress at work, to the point that I felt something was wrong with my health and requested a scan. The scan found a new small spot on my liver. A 2nd scan showed it stable. As a result of all of that and the incredible amount of stress and changes happening at work, I decided to request an accommodation to work from home. However my work is known not to be supportive and not to accommodate easily although many of my co-workers work from home based on previous operational needs. There is a whole process about it and it makes me very nervous as I have been told that the accommodation team basically grills you with questions, it takes months and they try to find a reason not to accommodate. I have no idea what to expect from meeting with them as I have already filled out all the paperwork stating my disability being metastatic cancer and the need for a stress-free environment to prevent a recurrence. Does anyone have any advice? I don't know what my rights are...my work is known to try to get away with as much as possible.