I'm probably like you. My toes are long and my feet need a lot of support, so a shoe that fits my actual feet usually severely cramps my toes. Like you, I couldn't even really tell what fit. In the last year I've completely revised my idea of what fits and what doesn't. My last pair of running shoes was a size and a half bigger than I'd been wearing (plus they're wide width), and my new hiking boots are even bigger than that (plus they're men's boots) and my feet are happy!

BUT, I don't think it matters as much with cycling shoes... my next pair of cycling shoes will probably be one size bigger, that's all. Even when I was riding lots of miles, there were definitely ways that my shoes had to fit in terms of arch support and not compressing the top of my instep, but cramped toes didn't give me problems on the bici.