This little mite may get quite depressed on its own: ducks eat poorly and lie around, head hidden in a corner or by a feeding bowl, doing nothing when they are depressed. You say it is snuggled up by you mostly -- it needs to be with you -- able to touch you and being handled/cuddled for 8 or more hours a day if it is to be happy. I had a rescued duckling that I did just that with last summer while I tried to find age appropriate ducky friends. Mine was 5 or 6 weeks and following me round [he wasn't imprinted on me but was closely bonded] before I thought to contact a local wildlife rehabber rather than other duck keepers seeking ducky friends. My muscovy, initally got 2 ducky friends from the rehabber -- a muscovy and a pekin -- and settled down well with them, but was put out when it came to moving out to the duck coop from my house!! He still sneaks inside when he gets a chance and if I have him inside to talk to my family on Skype, when I put him down, he doesn't toddle off back outside like the other ducks do, he heads as if for the door but then makes an abrupt right had turn and goes and tries to hide in my bedroom!!
I really think that your duck does need ducky friends and will be happier leading a ducky lifestyle outside rather than being a house duck. If he is a house duck he is your close buddy for life -- and that could be for 12-15 years if you feed and treat him well. You have to take your house duck everywhere as ducks are social beings and need company. He will be very distressed left alone while you are at work or out for the day. You will have to take your duck on vacation with you. Having ducks is a commitment, but having a single house duck pet is a huge commitment. You won't be able to change your mind when he is 1 year old and decide he should be outside with ducks -- by then it will be too late. Did I mention that mine is still put out that he has to live in the duck coop? And he has been with his ducky friends since he was 6 weeks old!