2 day old baby, feeling like a failure

M
Just had an appt with a lactation nurse. My nipples are wrecked cause his latch isn't great. He's lost more weight than they'd like so we have to recheck tomorrow. They are sending me a hospital grade pump today so hopefully my milk will come in. It's really hard not to feel like a failure. Nurse suggested I pump or hand express colostrum and spoon or syringe feed it to him after feedings. My nipples are killing me and he nurses for 4+ hours nonstop at night. I'm so upset and scared for tonight. Nurse showed me tips for a better latch and I fed him at the appt but he wouldn't stay latched correctly for long and we constantly have to retry. 
I'm so upset and frustrated.