Is it that you don't want to stop nursing, or you want to keep him on breast milk? If you want the bonding time when nursing, then I'm not sure what advice to offer; but if you are ok with stopping the actual nursing, then it may be better to keep him on pumped breast milk so he's getting a bottle whether he's with you or at daycare.
I was never very successful with breast feeding, and I admire those who are. I didn't have enough no matter how often or long I fed or pumped with either of my little ones. Even tried the reglan routine...
Anyway, in my opinion, I wouldn't be quick to blame his inconsolabilty on the breast feeding entirely. So many things upset little ones at this age (teething, etc.). So if you feel strongly about it, then stick with it, as it may be entirely something else he's dealing with. Is he on cereal/solids? If not, he may just be hungry and the milk isn't enough for him. Whatever you chose to do about the actual nursing, try to keep him on breast milk as long as you can. Good luck to you!