Today, 04:34 AM
I've been there and it's awful. I used to dread every feed, and be in tears when my daughter latched. I was also told her latch looked OK, though it could be a bit shallow at times - and she pulled on and off all the time as well without relaxing her grip, which was agony. Everyone told me it would be better by 6-8 weeks, and it wasn't. But, it did eventually get better for me, though not really pain-free until about 6 months I'm afraid.
Things that helped me were trying different positions, partiularly laid-back nursing and letting her latch herself, side-lying nursing, swapping positions regularly throughout the day so that the pressure was on different parts of my nipple, a lanolin-based nipple cream, and more than anything else - time. I think she just got bigger and better able to latch, but she's still not amazing at times.
Also have you considered oversupply/fast letdown? I had issues with that, which I think was causing at least some of the pulling on and off as she couldn't keep up with the flow.