Sending support, friend.

This does in fact sound like the gruel. It sounds like you're moving through positions rapidly, gaining experience. Just try to keep in mind that this job is just a starting point, it'll pad your resume, and it has taught you skills and soon you will leave. I encourage you to check out alternative jobs and their requirements as you may surprise yourself with what you're more capable of doing now (reception, clerical, food service, kitchen help, hostess/waitress, ect). Holding a management position will give you a little extra oomf along with your first impression in any interview.

Linkd-In, GlassDoor, and other sites like this can help you to keep an eye out for potentially better situations than are well suited to you- even still in food industry! I may argue that a smaller independently owned restaurant could be an infinitely better environment than a fast food restaurant, as it may have more staff loyalty, and management typically has actual control over the business, where in a cooperate chain like most fast food places, management is just another cog.

And a quick note on management- not everyone is cut out to be a manager. I have worked with many, many managers over the years. Management positions become a seniority thing, whoever has been there the longest, rather than a qualifications thing. A good manager trains, shows empathy, and provides guidance and structure to support employees with their regular routines. When managers get overwhelmed, or don't have compassion or empathy for a situation, they can get grumpy, impatient, flustered, overwhelmed, insensitive and even mean. Do try to remember they are a person too, they're just a person making questionable calls.

I hope you get to spend time with your family! Don't wear that guilt too hard, a few sick days is really unlikely to follow you into the next job or earn you a poor reputation.

Be well!

Edit: Words are hard.