My heart breaks for you, I just lost my cat on June 24th, also unexpected, I loved her so much, just like you. I've been telling myself I gave her the best possible life a cat could have, or maybe even a person.... please don't blame yourself I did that and it doesn't solve anything and it...
I feed my rescue Friskies she seema to like it, I've tried the more expensive brands and got mixed results with Nina...so I went back to Friskies, for me it's affordable, Nina likes it and her fur looks so much better shinier and softer...