charliemoo:your best bet would be to ring up various feed companies
To pick up charliemoo's theme. I have done some work at various of the companies who provide feed through the retail sector. and, at the time, they all used 'independent' nutritionists. Have you also thought about being a human nutritionist? I reckon that that is a sector which is increasingly coming to the fore because of concerns about human health and a likelihood of food shortages.
Whatever you choose however, don't get too depressed. We all have 'off'' periods in our lives, but the fact is that life is wonderful when we see it that way.