If you can just grocery shop once a week or every 10 days it will limit any exposure... it might help to ask friends or family to pick up the extra essentials you may need like eggs or milk. We also have businesses delivering free food for people financially hit by the stay at home order, maybe you have something there like that?
But if you do have to go out then wear a mask & glasses since you have a health issue anyway, gloves wouldn't be a bad idea (use winter gloves & wash them after every use if you don't have disposable gloves) and wash your hands and wipe down your groceries after shopping. The cases around here seem to be from prolonged exposure to someone coughing, not sure if that is the case everywhere.
Lots of people are using a free pattern for facial masks and wearing them, just remember you need to wash those after every use...they just help limit exposure not filter the virus.
Stay well!