Nervous!

My baby started latching about 2 weeks ago but I'm not feeling confident at all. She was preterm and we had a rough start to breastfeeding and I was pumping milk for her and giving her a bottle. Knowing how much she had to eat was one pro about exclusively pumping.

Sometimes when she latches it seems like a bad latch because its painful. I also noticed some lumps in my right breast and I believe they were clogged milk ducts.I was able to massage and then pump and they're gone now but does this mean that my baby is not emptying my breast fully and I need to pump afterwards?

Also I'm so afraid I might be starving my baby! She is having plenty of wet diapers and seems content though. I need reassurance and any BF advice anyone might have.