@Janna25 If breakfast is showing in guest view, but not in your listing preview, you need to contact airbnb so they can remove it.
For guests who have already booked expecting breakfast, how about just providing yogurt, fruit and granola, that seems easy and you can just leave that stuff in the fridge and let the guest know it is there for them, as well as whatever way there is to make coffee. If anyone complains that they were expected some full cooked breakfast, you can explain to them that the breakfast amenity appeared on your listing without you doing it, and that you are working on getting it removed, that you would never have offered breakfast since you need to go to work in the mornings, but that you are providing breakfast makings until it gets corrected.