Sarah, is this something you have had in the past, or is it a new thing on this round of tests?
One of the potential causes of elevated urea is dehydration. Is it possible you were dehydrated when you had your test bloods drawn?
In terms of cutting down on the protein, I envisage that's trim back a bit, not cut protein out. For myself, if I am finding myself in a hungry phase, I find a mixture of protein and fats the most effective way of stemming the feelings, so maybe it could be worthwhile trimming back on the protein a bit, but adding in some extra fats? The extra fats could come from fattier cuts of meat, as well as the usual suspects of butter on veg, or cream in sauces or with berries.