I absolutely agree with the other mamas - if there is any way to get your baby back to the breast, please try!!
With Emily I was so worried about losing my supply that I concentrated on pumping and "forgot" to keep trying her at the breast. In the beginning she couldn't get any milk out of my flat nipples - the adhesions wouldn't let her pull them back into her mouth and draw the milk out. So then close to week 12 I was really feeling bad about giving up and when I put her on my bare chest, she went right for my nipple and was able to get the milk out - I could see it in her mouth! Unfortunately it was right before I had to return to work so I didn't have a few weeks to work on it. At 8 weeks your little one should definitely have the instinct to latch on. I really recommend trying, particularly between feedings at first so he/she's not expecting milk right away.
As far as the nipple issues, I had those big time. Like gritting my teeth turning on the pump for MONTHS. No way to avoid it because flat nipples don't have that nice border around them that stops them from expanding in the tube once you have one big enough. The itching might be caused by some extra skin buildup that doesn't get sloughed off by the pump the way it would by your baby. For me, milk would end up kind of crusting up in the dry skin and I'd have yucky yellow flaky stuff all over the end of my nipples. No thrush or anything, just reallly gross.