Do you have a hydrometer? That will tell you how much water you need to add. You likely have enough honey to make about 3.5 liters but perhaps less, depending upon the honey. Just stir in water (stir well to completely mix) until you reach an SG of about 1.090. Stir (or shake) well to aerate, add your hydrated yeast (D-47 would probably be a good choice) add 1.5 grams of yeast nutrient mixed with a little water or must) with DAP (Fermaid K is recommended) after about 12 hours, another 1.5 grams when the gravity reads about 1.060 and another 1.5 grams when it reaches 1.030. Stir vigorously twice a day (to aerate) for the first three days and rack to a fully topped up secondary at about 1.010. You might want to reserve a little of your honey, say about 175-200 grams, to backsweeten after it reaches .994 or so.
BTW - never add the nutrient directly to a fermenting mead or wine without mixing with liquid first unless you want a gusher!