Feeling Guilty

I'm having a hard time breastfeeding Hailey lately. She wasn't eating at night anymore until this teething thing happened. She is waking 2-3 times a night. When she wakes between 4 and 5 the only way I can get her back to sleep is to feed her. She's not hungry when she wakes at 7, obviously because she just ate. I try to feed her before she goes down for a nap around 8:45 or so but still isn't really hungry. She eats for about 5 minutes. She wakes 30 minutes into her nap and I wonder if she's hungry, so I try to feed her. I don't know how much she's ate and its really screwing everything up! I find myself feeding her whenever she's fussing because I don't know if she's hungry! It's driving me crazy. I stopped nursing Cheyenne around this time and felt guilty because I don't think I tried hard enough to continue. Her not eating regularly is starting to affect my supply and that's a whole other issue. I want so bad to continue until she's a year old, that was my goal. It's so hard, especially with Cheyenne running around. I thought that the hardest part was behind me...feeding every 2-3 hours. She should be eating about every 4 now, but I find myself offering to her every 2. I'm just so tired. I feel so guilty, but on the other hand I think I could be *happier* and not so stressed if I didn't have to do this anymore. I'm just torn. I'm tired of pumping, tired of it all. I want to burn that darn pump.