I'm sure most parents of teens could echo your comments; the teen years can be confusing -- not just for teenagers but also for their parents.
I'm not a psychologist, of course, but as you look back over your own adolescence, you know these can be difficult times. On one hand, teenagers yearn to be free and have all the privileges of adulthood. But on the other hand, they're beginning to realize that adulthood also involves responsibilities -- and they find that scary. They also are dealing with a host of other issues, from peer pressure to a new yearning for love and acceptance.
God has given your daughters to you -- not just for your enjoyment, but also so you can guide and help them make the transition to adulthood. Thank God for them, and ask Him to give you the love, patience and wisdom you'll need for this stage of their lives. Someone half-jokingly once said to me that James 1:5 must have been written especially for the parents of teens: "If any of you lacks wisdom, you should ask God... and it will be given to you" (James 1:5).
Go out of your way to let them know you love them, no matter what's going on in their lives. Learn to be a good listener also, and to know when to give advice and when to keep silent. Learn, too, from the experience of other parents. Most of all, encourage your daughters to put their lives into Christ's hands, and to seek His guidance for their futures.