This might be a little late, hopefully you've sorted out your problem. It's all about adjustment with diabetes. I've had it for nearly 16 years (I'm 24) and I'm still tweaking now. It might feel as though Diabetes is taking over your life where you need to constantly check what you're eating and being confused when something isn't working, but it becomes second nature to double check whenever you change your routine or do something new. Heck, whenever I get ill, my levels shoot right up into the 20s!
It sounds like if you're suffering from hypo's in the afternoon your afternoon insulin dose needs to be reduced. As for being higher later on, perhaps increasing your long-active dose will fix it.