Hi alohajourney, welcome to the forums!
Two stone is a fantastic achievement! We would love it if you would add your data to our progress tracker (see link in the top panel or side panel)!
I posted some information on this yesterday, I think it was in the Resources section. There are some ideas there for how to deal with the plateau. The first thing is to count your calories on your feast days for a while - it could be that there is some food/drink that you are having that is adding a lot of calories (it doesn't sound like it from your post though). Second is to work out what your new calorie requirement is since losing weight (there is a link to a total daily energy expenditure calculator in the resources section). If you are eating more than this on your feast days, it could be that the fast days are not creating enough of a drop in calories. Remember your fast day allowance is actually a quarter of your normal calorie requirements so this goes down as well

.
We have had a few people asking about weight loss stalling but I'm not sure that we have anyone who has experienced no weight loss for several weeks. Most are just a one or two week thing before things move again. We don't really know if weight loss plateaus are less common or easier to overcome with 5:2 or whether it makes no difference what diet you are on!
As well as my comments about looking at not overeating on feast days, it seems that some people have found they don't lose weight so well if they under-eat on feast days.
Hopefully someone will be along who has had first hand experience of overcoming the dreaded plateau!