Thanks, red!
I still don't understand why he is having formula at home, though (apart from the well-established 11 pm bottle).
I suppose it is because you are trying to get him established on a bottle at other times, yes? because that is when he will have a bottle at nursery? I don't see the point of this, though. He can bf when he is with you, can't he?
Now, I don't know you, don't know your baby, I'm not a child psycholgist blah blah blah.....but with those disclaimers, I believe, and my experience tells me, that babies are trying to tell us something when they refuse their feeds consistently.
In your case, could your baby be trying to say he is going through too many changes at once? That nursery is a change, and the feeding regime you are putting in place is a change (solids and bottles) and he is unsettled by it?
I don't think you would lose anything by just offering him breastfeeds at home, and forgetting about the bottle at home - totally. He is capable of taking a bottle at nursery, so you don't need to be concerned about his 'skills'. How about just going back to full bf at home (yes, and ditching the solids for the moment, or leaving it to the nursery to do) ...this will take a few days of luring him back to the breast, with skin to skin and so on.
Just an idea - I do think you'd benefit from calling someone, too.