500 mg is a lot. Like that should be the whole package, and that would be way more than I would see in AZ dispensaries. 5-10 mg is starter dose, but goes up from there with tolerance. Assuming a 25mg dose 3x daily (which is a bit much but not a whole heck of a lot), 500 mg should have you set for about a week. Even 50 mg (guessing typo?) is a pretty intense gummy unless your tolerance is about where mine was, when I would consume the equivalent of a gram of flower daily. That's a quarter ounce per week, which is a moderate to high rate based on my own informal research. Sooo if your friend brought you 500mg gummies - they must think you really need it.
I do feel for you. Getting more than you intended to take is rarely a pleasant experience. Usually if your dose is too high you start to see the negative effects such as increased heart rate or anxiety. Yes, in addition to cutting down trees, I also have experience smoking trees, which does NOT make me a doctor but really I bet I have more knowledge of MMJ as a patient than the average physician would.