What you all are going through is something that most parents go through.

When my DD'd were young my MHN told me not to worry 'as believe it or not they will not starve to death'.
She suggested I don't worry about meat for a bit and tip bake beans over the veggies. Also feed them earlier an early tea.

This did work for me and they did eat veggies again only to have DD1 years later decide she didn't like peas. I mean, who doesn't like peas!!!!

Keep up the fluids while they are going through this stage and wait for the next instalment