Most of the medications listed have the doses on the bottle, and how often to take. I would hope that diabetics would know how to self administer their own insulin.
I agree with you, without proper training, you shouldn't self administer - but if you have the supplies and a doc or nurse happens to come along, they can help out with it.
You can pick up the book procedures for primary care physicians which goes over cleaning, debriding wounds and suturing.
You also can't do much damage with one bag of IV fluids for dehydration. Its also pretty obvious if you accidently cannulate an artery (spurting blood) instead of a vein.
Only ones here, would really be steroids and antibiotics, but there are protocols you can look up on medical websites (like SCCM, ABIM, AAFP)
famotidine 1 tab and diphenydramine 1 tab for an allergic reaction.
Had a patient I brought down to ICU this week who had COVID, former ICU nurse. She stayed home and treated herself with 100 mg of prednisone instead that she got from a friend.
You just can't solve all of it, but if you are prepared and resourceful and careful, I think it will be ok