Hi Lin
do you have friends with lo's of a similar age you could "do lunch" for the lo's with? The reason I ask is that when Sophie moved up into the toddler class at nursery she couldn't feed herself at all- 6 weeks later and she can feed herself an entire meal with very little help from me; she's learnt just by watching the other kids do it (and she's only there 2 days a week)
I think sometimes they learn better from each other than from us, iykwim?
Also Sophie eats on her own at home as we eat after she is in bed- I don't sit with her and watch her as that definitely affects her and like you say makes her eat less, I think she feels under pressure. I busy myself in the kitchen, perhaps doing the washing up or preparing veggies for dinner, chatting away to her while she eats in her highchair. My friend had a similar problem with her lo, she started to eat with him and it made a huge difference, so that's a good idea.
In the mornings could you perhaps do him some toast and bits of fruit for breakfast he can feed himself with his fingers, and he could be doing that while you put your makeup on or something? This is what I do on the days I am working to save time.
Just some ideas, hope there's something here to help you x