Given his anxiety, it’s not all that surprising that Tyson prefers to do his shopping online and have his groceries delivered as much as possible.
There are obvious exceptions such as collecting his meat from Jeremy’s butcher shop and collecting other pet supplies from his own pet store.
When he needs to enter an actual store, Tyson cannot simply browse without having to excuse himself to hyperventilate outback. He needs to give himself a clear mission to keep himself focused. This also leads to him not going shopping in person until it is absolutely essential to reinforce that sense of urgency to get the job done.
Generally, Tyson will create a map rather than a list of what he needs to buy. Technically there is a mental list of the items Tyson needs to get from each area, but when his anxiety is bad, Tyson can focus on the concept of a map better than recalling a simple list through his panic.
Retrieving things for his pets is always easier for Tyson to do than shopping for himself, then it matters more than himself; who ranks at negative twelve on Tyson’s priority order. This also applies to verses where Tyson is shopping for Sebastian or James as well as himself.
He can walk through a store without batting an eye externally when babysitting his nephew. His anxiety remains, clawing in the back of his mind, but when Tyson has to focus on his nephew’s needs, his own become irrelevant. More irrelevant than usual.