So basically, the hospital has you hostage so you must pay more for the same things you would have brought from home, or you don't pay and aren't healthy?

Yes. Because Health Insurance has a whole range of items/services that are not covered/paid for that the hospital still needs to provide to you for adequate healthcare. The workaround (because the system is broken as fuck) is to charge insane prices on the items insurance does cover to offset the costs of the items/services they don't cover.

On top of that, there are additional steps & processes to dispensing medication in a hospital setting vs. picking it up at CVS. You have an adverse reaction due to a drug interaction you didn't know about outside CVS, that's on you. You have an adverse reaction to a drug interaction inside a hospital, that is on the hospital and lawsuits aren't cheap...so you're paying for the Dr. to deem it medically necessary, the Pharmacist to confirm it isn't going interfere with any current or future drugs you will taking and then the Nurse to ensure you are given the correct drug, at the correct dose, in the correct form at the correct time.