Anyone else having trouble figuring out what size jeans you wear?

I've always had big thighs, butt,and hips but didn't really have problems finding jeans. I guess it all got bigger and wider because I can't find jeans that fit. If they go over my thighs butt and hips they are way to big in waist. And I don't have time to worry with trying to keep pulling my pants up all day while toting a baby, diaper bag,etc. Has anyone found a brand that fits good. I'm tired of wearing stretchy pants,even the ones that look like jeans. Please help!