Not to be negative but I just want to point out a couple of things:
Three weeks is not a plateau. The body can retain water for any number of reasons and look like your fat loss is stuck. Opinions vary but I would say eight weeks and no loss means you're at a plateau.
A refeed is not needed for a female above 20% body fat. A refeed is a period of time where you overfeed your body to normalize your hormones. This is something bodybuilders do on regular intervals but ... they are extremely lean and looking to get leaner. This is done to help keep the body from fighting further fat loss. Bottom line it's not natural for people to be heavily muscled and 5% body fat - so you need some tricks to get there.
All that said ...
You can lose weight from a single meal or a couple adult beverages. Not fat - but water is released. Stress is a big cause of water retention and can freeze the scale even as fat los continues. This is why you often see people posting about how they ate a "cheat meal" and they lose 3 lbs the next morning.
You may want to consider a diet break. No doubt if you've been dieting a while you've slowed your metabolism a bit. A couple weeks of eating higher calories can be helpful to continue losing especially for psychological reasons.
Hope this helps. Personally - if I were a professional and you were my client I would tell you to
take a diet break for two weeks if you're not on some specific time frame. Sounds like you need one.