Problems latching...

My daughter is 2 weeks old, shes a preemie, born at 35+5. The first 2 days she latched great, but then all of a sudden stopped. I've done suck training, which the lactation consultant suggested I do and she does great with that. She will drink great from a bottle, and if I'm lucky she will latch for a minute or two but then she just gives up. I pump 2-3 oz from each breast each time I pump so I know my milk is in...

Has anyone had luck with nipple shields to help? Or any other advice?

I breastfed my last daughter and didn't have any problems, I'm really hoping to get to breastfeed again (I can continue pumping, but it's a pain!), especially because she is my last baby.