could you buy a carton of canned coconut milk online? or perhaps go to an area where there's bigger shops (I think I read you lived in the "country") to do a bulk buy? there are plenty available without sulphites or any added nasties!
what about olives in jars? again, it might be something you could get at a bigger shop if you wanted to make a trip.
in terms of eating - most BF mums seem to eat 4-5 meals a day to support their needs and the needs of their bub. these are actual meals with protein/fat/vegies, not just a snack of nuts/fruit/avo. any vegies will work, and having a variety is