It is hard to meet those night time needs of baby. Is it possible for you to nurse baby lying down in bed. That way you would not have to get up and nurse when baby is ready to nurse. This is a great book and might be worth checking into.
Babies have different sleep patterns then adults do.
Actully they are suppposed to wake often to keep their breathing in check. In most other parts of the world moms sleep with baby next to them, roll over nurse and go back to sleep. This worked for me but each parent, couple needs to figure out what works best for them as far as sleeping arrangements go. I found that it was best for me to go with what my baby needed and throw out the clock and my night time expectations of sleeping for extended periods. Yes, it is not uncommon for a 7 week old to nurse every couple of hours thru the night.