You have my sympathy Buddly. My 2 (almost 3) year old has started nursery and this is his third week. Apparently mummy is able to leave him now, but he has his 'moments' when he realises she's not there and cries for her. Twice, recently, he has been at our house without daddy (who usually drops him off here ) and he has sobbed as my son is leaving. However, with a bit of distraction, he's stopped but then started again sometime later, and we go through the distraction process again. It seems to work. We've never had any problems like this until he started nursery.
It seems to me that some parents can drop their children off and they just get stuck in and play but other, more sensitive children, have a hard time initially.
I know how heartbreaking it is for us Grans who can't bear to think of the little ones being upset but, hopefully, it will pass and they will adjust being in a different environment without mummy.