First of all, you are not alone. You can see how many people have gone through similar things. Nursing made me cry a ton also because I just felt like it was something I SHOULD be able to do and it was the main thing I could give my child and he needed . . . so why couldn't we get it right? I thought we were such a failure. It wasn't until 6 weeks that I found out that trouble with breastfeeding is the norm among all my friends, not the exception. Some specific suggestions:
1. Get back to that lactation consultant and get some more hands-on help. Don't worry about the cost, I promise you'll pay more in formula if you have to go that route. She'll help you keep working on that latch. Be pushy with your l.c. if you need to be - make sure she understands exactly what your problem is and that it is URGENT. DON'T LEAVE UNTIL YOU FEEL MORE CONFIDENT WITH THAT LATCH.
2. Talk to her about a Supplemental Nursing System (SNS). That's the thing where you nurse and give a little formula in a bottle around your neck, through a tube, simultaneously. MAKE SURE YOUR LC USES IT WITH YOU UNTIL YOU GET THE HANG OF IT. I was never able to be coordinated enough with, but it does sound like it might be the perfect solution to your problem.
3. I did not have a baby in NICU, but I don't think 1 oz in two weeks sounds bad at all. They have standards for these things - certain % weight loss is a problem, but otherwise don't fret about it. I don't want to be the one to say this definitively, but it does not sound to me at all like you are starving him. Another good thing to talk to your LC about.
4. The feeling like you're constantly feeding for only a little bit of milk is totally normal and will eventually get better, I promise. This was the hardest part for me. Feeling like I was going to be doing nothing but breastfeeding and pumping all day, with no end in sight. But the truth is, one way or another, you will settle into a routine after a while and you'll get (a small) part of your life back.
5. This is your best window of opportunity though, so just think of this as your full time job for a few weeks - pumping to keep your supply up and working on the latch to get him nursing better and that's IT. ASK FOR HELP. Don't be shy - ask people you normally wouldn't dream of, if Dad is back at work or not in the picture. ASK FAMILY, FRIENDS, NEIGHBORS. Babies used to be raised by a community, the way we do it now is not normal. I didn't ask for enough help and then felt like I couldn't handle simple things, like making my own lunch and also pumping and breastfeeding - so I dropped a pumping or didn't eat and now I wish I had listened to people when they said to do nothing but nurse and pump and sleep and eat. Literally, feel OK with asking people to get you a glass of water if you need it.
6. Eat and drink a lot. More than you think you want to. You need it to build your milk supply.
7. Foods that support milk production: fenugreek and fennel tea (or any of those nursing mom teas you see around); oatmeal; quinoa; dark beer (it's OK, you can have one a day for sure). AGAIN, ASK SOMEONE'S HELP IN MAKING ALL THIS, BUYING IT, ETC.
8. Whatever is the outcome - NO GUILT. YOU ARE A FABULOUS MOTHER. Only you can make the right decisions for your baby and you are doing a great job. Every drop of breast milk you've given him until now has been a true gift and you should be really proud of yourself for it. If it doesn't work out, make sure you remember this. You have given your baby so much already and you are going to be giving him so much for your whole life. Work from a place of strength, not fear. Focus on every drop he gets, not on the ones he doesn't.
9. Know that however this settles out - there is a wide spectrum of how people breastfeed. Exculsively pumping, breastfeeding and supplementing, you name it. I am at four months and I have been through every breastfeeding scenario you can name. We finally settled into a routine where my son nurses only at night, we feed formula and a little pumped milk during the day. Mostly, he gets formula. This does not sound like where you will end up - you are doing much better than I was at 2 weeks (GOOD FOR YOU!). I'm telling you this just so you realize every little bit of breast milk is helpful and you are doing great and don't be afraid - THINK POSITIVE.