Breastfeeding hurts!

My baby is 3 weeks old and breastfeeding hurts! 
My nipples are constantly sore and are excruciating during feeds. 
I've asked 3 times to be referred to a lactation consultant. The first time in hospital but they said give it a few days because it always hurts at the start. 
The second time the just forgot to call them. 
Today I called directly and they said they'd call me back but they haven't.
I'm desperate for some help with this.  
I cringe every time I see hunger cues and I cry through every feeding session.
I've watch so many videos but I just can't seem to fix it.