Your carbs during and after the ride should be fast carbs, e.g., simple sugars and carbs. A glass of orange juice with a scoop of vanilla protein powder is a great after-ride drink. Be sure you're taking in carbs within 30 minutes of getting off of the bike.

I would back off the Saturday mileage and add rides during the week, as others have suggested.

What kind of bike are you on? If your bike is really heavy, you are expending more energy on those rolling hills than your riding buddies.