Start gravities at the higher end, are notorious for being harder to manage. They tend to need a more considered method/technique.
Just chucking extra yeast in there, or racking off and adding a different one with a higher tolerance is unlikely to work. Search for "restarting stuck ferment" for an idea of what might be the best next step. Also, you should check the pH, as low pH/high acidity can cause a stuck ferment. The lowest pH should be about 3.0, anything lower is likely to be an issue.
If the nutrient was just DAP, then that may also be a pointer. Honey is low in nutrient i.e. nitrogen based compounds, which is solved by DAP, but it also needs various micro-nutrients, usually supplied by the use of something like Fermaid K, Fermax, Tronozymol, etc etc. The example is, when working out the nutrient requirement, for something like 70/30, Fermaid K (or similar) and DAP. The Fermaid K type nutrient supplies the micro nutrients and some of the required DAP, but the extra DAP then augments.
Higher gravity musts often need SNA (staggered nutrient addition) methods used on them, to get the best out of the yeasts.
For the newer mead maker (whether with other fermenting experience or not)
the Gotmead NewBee guide is where I point people as it seems to be an excellent guide.
{edit}p.s. I notice you're in Manila, so could ambient temperatures also be an issue, causing the yeast to be stressed ? I understand the whether gets hot there, and with yeasts like D47, it's entirely possible that you'd end up making paint thinner.......{/edit}