Ok, so what Golddiggie is alluding to, is that there is the wyeast sweet mead yeast which is only tolerant to about the 11% ABV mark and its also finicky as hell to use - to be honest its a complete PITA.
There's also the white labs one, which I presume youre referring to that is tolerant to about 15% and has a much better reputation.
Now without access to my usual table to check, if it is at 15% or thereabouts, you'd be hard pressed to pitch another yeast, even doing an acclimatised restart and get it refermenting to drop the gravity down more.
Ok, just did a quick check on the pc and your 98 point drop equates too 13.3% ABV. So you try a restart but I'm not sure whether you'd get it to restart with a yeast that has "sharper teeth".
Your main issue is likely to be that if its stopped fermenting, the current quoted gravity is very much at the top end of "dessert mead" and likely to be cloyingly sweet. If you find it drinkable then that's great but I find batches that sweet a bit too much.
So, if some stirring and maybe either FermaidO (as different from the "K" nutrient) if you can get some or just try boiled bread yeast, to see if you could knock the gravity down a bit further, or if you have access to a dry mead of similar type you coild blend them or you could even just fortify it with vodka or everclear.
I suspect that the main thrush of Golddiggies post was that these so called "mead yeasts" seem to have issues. To start with how the hell do the yeast makers know what strains were originally used for meads as all the historic recipes make no mention and that yeasts/ferments weren't understood properly then. And with written records being little to non-existent it would seem that to call them "mead" yeasts is little more than marketing bollocks. It doesnt help that the majority of HBS know little or nothing of mead making and often make rubbish recommendations for materials and ingredients.
Its why most recommendations come from wine making technique and the experience of regular mead makers.....
Liquid yeasts seem to have a harder time with meads anyway, can't say exactly why but I suspect its connected with the much higher levels of sugars generally found in honey musts, plus the lower cell count and mead makers not generally making starters (just either straight rehydration or rehydration using GoFerm).