Make sure your flanges are the correct size, they can rub if they are too small. I had some pain with latching and initial let down until about 5 or 6 weeks myself. I really felt like it was more comfortable when DS was a little bigger and his latch was wider. He never had a bad latch, it was just easier as his mouth got bigger.
I also had some more soreness around 8 weeks, because I feeding and pumping pretty often to build up a freezer stash. That got much better when I went back to work.
For cream, I always just used lanolin.