Can you get to Petsupermarket as well?If you can they generally have Higgins products,and most stores carry Carefresh as well.Oxbow foods aren't that great(even garden select,which includes tomatoes which are generally considered unsafe,and it's quite high in fiber which could be problematic at the levels it has).Kaytee(the brand for FortiDiet which is loaded with artificial dyes and includes synthetic vitamin K aka menadione which isn't very healthy plus the GA is unsuitable)are quite the awful brand for food,so I'd change that out as soon as possible without transitioning at all(feed a high quality maltodextrin/fructose/sorbitol/dextrose/etc free probiotic that is completely natural and a little bit of pureed pumpkin for digestive support)as it is a very low quality food.
I wouldn't buy any more of the mealworms if they're from China(and if they are I'd just throw them out and never feed them again),as mentioned before.It's not worth the risk(China has terrible standards for pet products,and a lot of Chinese products have killed many pets because of these awful standards regardless of any manufacturer's claims you might see on some products).You can get the Pure Bites in stores in Petco,Petsmart,etc even if it means using only chicken,they should have shrimp too though.
Petco should have the Vita Garden in store,so as far as not being able to buy online goes you should be fine
If it helps any,this particular food could technically be fed to Syrians and dwarf hamsters(including diabetes prone hamsters like hybrids).If you had to feed one food to both hamsters,this would be the ideal food for that.It's high quality,no unsafe ingredients(including no artificial dyes or unsafe preservatives),and not online exclusive!