Hey Jennifer,
I'm a big fan of Greek yogurt. It has more calories & almost double the protein of regular yogurt. I like to mix a cup of non-fat plain Greek yogurt with Muscle Milk. It's like ice cream. I also like apples or bananas with almond butter, and there's always fresh fruit, cottage cheese, cheese sticks, putting a little bit more meat on your sandwich, etc.
Are you using a recovery drink? If you haven't tried Beachbody's Results & Recovery Formula, you should; it's really good! You could also use non-fat chocolate milk, or 8 oz apple juice mixed with a couple of tablespoons vanilla protein powder.
All these little things can add up and keep your energy levels on the rise. The timing of nutrients is also critical. I have an article on my other computer. I'll post it later this afternoon.
Sounds like your boyfriend is a tad scared of Insanity!

I actually had someone tell me that the exercises didn't look that hard. Yeah, by themselves, they aren't. But string them along one right after the other, and you're in for a butt kicking!