Breastfeeding :: Need To Start Storing Milk

My baby girl was born this last Wednesday. So far everything has been great breastfeeding wise. If anything, she tends to fed twice as long and go twice the recommended time between feedings, but that gave me time to rest.

Today, I've had a terrible time getting her to feed for more than ten minutes every few hours because they gave me a stronger pain medicine which also puts her to sleep whenever I try to feed her. I've decided not to take it anymore unless absolutely necessary.

Anyway, we finally get discharged from the hospital and my breasts are so sore and full that I'm pleading with baby to stay awake through a whole feeding. I didn't think milk would start coming in until later, but I swear when I finally got to pumping it out manually, it looks like milk instead of colostrum. Baby finally woke up long enough to feed fully too. But no matter how much comes out, they feel like they just fill right back up again and get sore... how do I stop the pain?

It feels like my body is producing more than what baby needs. She's barely a few days old. She doesn't need so much to be full. I'll need to start storing milk late for when I return to work, but I don't even know if this is milk or colostrum. How can I tell?