Nancy, I'm so sorry you are having a rough start.......more
The most important thing for you to do is to see an experienced LC in person. Here is how to find one in case the hospital LC can't see you very soon:
http://boards2.parentsplace.com/messages/get/ppbreastfeeding176/11/1/1.html
Are you exclusively bf at this point or offering any supplements of expressed milk or formula? Is the baby pooping and peeing enough, gaining enough? Tell me how many times a day you bf, how long it lasts and how many poops and pees per each 24 hours.
You are right that when she loses the seal easily that is a sign that something isn't right. There are many things that can cause this but a shallow latch is the most common. Shallow latch can also cause nipple soreness and difficulty for the baby to get adequate milk (although some babies deliberatly position this way to slow a too fast flow of milk)
Here is my description of position and latch to tide you over till you see the LC:
http://boards.parentsplace.com/messages/get/ppbreastfeeding77/45/1.html
Try to get really comfortable with the one armed hold you will use at the breast with the football or cross cradle hold. (definitely don't even bother with the cradle hold in this situation until you are more comfy with the latch) Practice holding the baby that way (one armed) even when you are not bf. Hold her head with your thumb and index finger low behind the ears. Your palm should support the neck and upper back and your arm should support/cuddle in the rest of the baby's body with your elbow pulling in the bottom. The most common problem I see is that moms don't hold or support the whole body or they don't hold it firmly enough. If you are holding firmly with your whole arm the baby won't "hunch up". If you can walk around holding the baby this way you have it right. If you don't feel secure enough to walk around with this one armed hold something isn't right. Many times I have a mom hold the baby that way standing up or sitting without the pillows, then after the baby is secure in that one armed position mom sits and then I put pillows under the arm for support. It may seem like a fine point but if you put the pillows there first you generally will depend on the pillows instead of getting a firm grip on the baby in your arms which is how you will control the latch. If your baby is "darting her head forward to the nipple" that probably means you do not have a secure enough hold on her. Your job is to control the moment of the latch, not to allow the baby to control it, you have to control the head and the secret to that is controling the whole body. You can not control the latch if you don't have control over the baby's body. As you hold your breast with the other hand to latch hold that closest baby's hand between the pinky finger and ring finger on the hand that is holding the breast. That gets rid of one of the hands. It is common for babies to have their hands in their face when hungry, it is not that the baby is doing it on purpose to inhibit the latch or as a way to reject mom as many moms misinterpret. If you need to have some help with the other hand have dad or grandmom hold the other hand just with latch. As you get better at it the baby will learn to keep the hands out of the way. Some moms can tuck that other hand under their armpit of the arm that is holding the baby...depends on your body type though.
If your baby is losing the breast when she pauses that can be shallow latch and/or retracting nipples. When this happens I have moms not only hold the breast to do the "sandwich" technique but squeeze very near the areola and very firmly to "shape" the nipple/areola so the baby feels it in the mouth. When I do this I generally hold that compression of the areola until I am sure the baby is sucking well. My fingers are so close with this technique I am usually touching the baby's lips (this is not a technique for all bf concerns, only very specific ones)
Here is a post that describes the technique and the reason behind it with preemies and some term babies. It also goes into the appropriate use of a shield but I would not recommend that for you unless the LC who sees you thinks it would be useful and can provide the appropriate follow up:
http://boards2.parentsplace.com/messages/get/ppbreastfeeding251/23/1.html
If she is doing some nibbling after the serious sucking remove her from the breast. Don't allow her to stay on and do any "incorrect" sucking or positioning it will only reinforce it and she will continue to do it. You would be surprised how quickly babies can learn to change behavior with positive reinforcement. If she still needs to bf try to re-latch or switch sides.
In addition to compressing the breast to keep her sucking you can also try stroking under the chin from chin to adam's apple with moderate pressure. It is important to stroke only in that direction and not adam's apple to chin.
I can certainly understand why you would feel like giving up, but I want to reassure you that there are many positive signs that with the right help you will make great strides. When bf is going well it is sooooo easy, I think you can get to that easy point, hang in there a bit more. We are here for you as much as you need us but also get that experienced in-person help in your community.
Keep us posted
Warmly
Kathy