Breastfeeding positions

I had a preemie, and with him being so small and my breasts being so big... We pretty much ALWAYS use the football position. He is almost 6 weeks now, and finally over 7 pounds. Now that he's a little older, I have been going out more, and the football hold is, by no means, the most discrete nursing position while in public. The problem is, it is very awkward and frustrating for both of us to get started in the cradle position... And when we finally do, not only do I feel like I'm smothering him, but I don't think he is as efficient at nursing in that position. He will nurse FOREVER and I will still feel full, and he doesn't seem satisfied and will still be fussy. I don't know if he's still just too small or he just needs more practice nursing in that position? I'm at a loss and it makes going anywhere stressful. Why would the nursing position he's in affect how much milk he's getting?