wow, this is a tough decision. I personally think that any yorkie needs a lot of attention, and it seems you two cannot provide that to the little one. I think even being in a daycare everyday would suck for the little one and i think its best that you find him a new home now that it has only been 2 weeks rather than waiting until you get more attached to him and it becomes a harder thing to do later on when you realize its still not working out. Either way i wish you the best of luck on whatever decision you make.
