This is the beauty of self testing! You have learnt a valuable lesson.
Do you have a Lidl near you? They sell low carb rolls (about 9g carbs per roll) They are called High Protein Rolls, sell at 29p each, and can be found in the fresh bread baskets. They are dark brown, triangular, and packed with seeds. I slice mine in half and just have half toasted with butter. I find a half is enough because they are very filling. They freeze well.