Pain while pumping and pink ring around nipple?

Anyone else have pain while pumping and pink rings around their nipples? I've been pumping exclusively for about 3 weeks and I'm not sure what's causing the pain or the rings. I use a medela pump in style advanced and the 24mm flanges, and I notice that a lot of my areola gets pulled into the tunnel (nipples don't rub agains the tunnels though). Could it be a flange size issue? I did try 21mm and 27mm and haven't noticed a difference with the pain or rings. 
The pain is getting to the point that I'm debating trying to make breastfeeding work (baby has a shallow latch and never opens wide, I'm getting kind of desperate for relief!)