"Never Wake a Sleeping Baby"...

...Isn't that what you've always heard? Well, Lilly sleeps and sleeps and sleeps. She isn't gaining her weight back and now weighs 7 lbs 8 oz and she weighed in at 8 lbs 3 oz at birth. Today, her doctor explained to me that she doesn't have enough energy to wake up and eat because she isn't eating enough. Hmmm... so, I seriously spend an hour trying to wake Lilly to eat. I strip her down to her diaper, change her diaper, rub her with a wet wipe, tickle her feet, massage her... and then maybe she will open her mouth long enough to eat for 5 minutes before she falls back asleep. I then try to have her drink either pumped breast milk or formula, but she will only drink about 10mL before she falls back asleep. I am able to get her to burp about 50% of the time but when she doesn't burp, she ends up spitting up almost all that she has eaten. I am so frustrated at this point b/c I hate having to irritate her and I am getting very discouraged when I stuggle so hard to wake her up and then face the challenge of keeping her awake! I feel so guilty for complaining because I have waited so long to have Lilly here but I am so exhausted. Today, when I was finished pumping, I went to turn off the breast pump and instead grabbed the remote and turned off the tv. I need some sleep! Does anyone have any secrets to waking a sleeping baby? Please help!