Hello there, I was going to suggest that she might be going through a false pregnancy, it is quite common for unspayed does to think they are pregnant, when they are not. So they go through the motions and build a nest with hay and fur and a few weeks later they’re back to normal. That being said, does experiencing that usually pull fur from their chest and stomach, not from their back. Is she building a nest with her fur, or does she just leave it laying around everywhere?
It’s possible that she has some sort of irritation such as fleas or mites. Mites can’t be seen with the naked eye, however you can treat for them. I’m not sure if revolution is available to you there without a vet prescription, but it is commonly used to treat for parasites on rabbits. I believe the kitten dose is the one used for rabbits. You will need to dose two separate times to catch the whole life cycle. I would also recommend washing or replacing any bedding and thoroughly cleaning out her hutch and cage a day or two after you dose her. Fleas should be fairly obvious on a white rabbit, I suspect you would have seen those when you looked.
Keep in mind that these are only a couple of possible solutions and we can’t diagnose your bunny, there are probably many more things that could be going on, but without access to a vet it’s a good place to start.