I’m addition to convenience Amazon has just killed off a lot of retail options. The only competitor left with brick and mortar is Walmart and somewhat best buy for electronics. Very hard to find those small specialty stores nowadays for little random things unless you live in a big metropolitan area. Even stores like Walmart now will have the same products by a million different brands instead of having an actual variety of products.
It is most likely this. OP is one of the unfortunate people that just cannot use marijuana safely due to his biology. If you have cannabinoid hyperemesis, best to stay away from weed because the constant nausea/vomiting can lead to unintentional weight loss and a lot of other physical problems that are no fun.