Sublets/ guest house rent how do you find

I feel it be cheaper renting from someone directly rather than through company. Needing a QUIET place within 25 ish minutes of downtown area to get to Dr appts easier . I'm have multiple chronic conditions with too many food & chemical allergies to list so unfortunately can't rent a room in a shared home/space without going to the ER each night. Just need it to have cooking access, clean a/c , respectable quiet area is a must (I sleep alot during the day), and no flights of stairs (wheelchair).

Where can I find open spaces for this? Feel like Craigslist would be too scary for me (28 F). Or does anyone have any leads?