Im going to give my oppinion but I am not as experienced as Squatchy or others so you may want to hold on till you her their advice aswell
You can easily have that bottled in 3 weeks. however, it wont be "good" by any mead standards. There is nothing wrong with doing meads without nutrients (In fact there is a type of mead called Show Mead that is only water yeast and honey). But not using them greatly slows both fermentation and aageing required. The only reason why this tasted any good to you is because its megasweet. SO the only actual way to have anyone drink this in 3 weeks and think it tastes any good is if it has a shitton of residual sugar. Some meads do this, but not most. Its not for everyone palate and even with this kind of overly sweet meads they are recomended to age long.
If i were you i would try boiling some yeast (bakers yeast, cheap one, not the one you use to ferment mead) for 5 minutes or so and then add that to the must. that would give some nutrients to the active yeasts (yes, they cannibalize) and help the ferment a bit.
Im sorry to tell you that, even with the new practices that make aging times way shorter, that mead wont be good in 3 weeks. You will learn patience the hard way. Dont worry, most of us tried to get meads to be good faster, but you need to have patience anyway. If you want fast mead check out the BOMM recipes.
Understand that 1.162 is a super high gravity. this is bad for the yeast. the fact that you didnt add nutrients does not help, and it seems you didnt degass or aereate either. because of this, the yeast will produce a lot of off flavours. those will dissapear with time, and you dont taste them now because the faults are covered by the superhigh ammount of sugar.
If you STILL want to try and have it ready in 3 weeks, put the carboy in the fridge or somewhere with 4ºC or less for a week. Then rack and stabilize with sorbate and sulphites. Wait two weeks and bottle. This will yield a very very sweet tasting mead, cloying probably. However, i think its best if you let it run its course, try to feed it and take your time. With that gravity and the absence of nutrients, you will have a sweet mead nonetheless. we are talking about 5 gallons here, its not 4 bottles what you are risking.
About the grape flavour...well it has happened to me too. i dont like it so i dont ever add raisins or grapes to my meads. but that is just personal preference.