If you are in a position to keep the economy going there is nothing wrong with shopping or buying online, whether essential or not.
It's people in this position who are able to keep the economy ticking over, even if it is just the odd delivery here and there.
Yes, a lot of us have lost jobs, income etc, and can't afford, but life goes on.
There are enough posties and delivery drivers, they need to keep their jobs too. Please don't feel guilty for buying stuff.