Clothing size and fit is certainly not an exact science, is it? For what it's worth, I'm 5'6", but I'm so doggoned short-waisted that I wear Petite sizes just on the top. On the bottom I wear regular sizes.
What store has the clothing you like best? If it's Ann Taylor Loft, go in (without children along) and ask for someone who can help you with fit. You aren't the only person who finds it all challenging, and a sales professional will be glad to take time for you if she realizes that you'll make a purchase if the size thing gets worked out. It could be that you'll find a solution; if not, ask her where you should look for pants, and stick with that store for the tops you like.
I'm not going to tell you where I shop because it won't help you - I'm way older than you are.