Kim,
congratulations and congratulations again for nursing your baby!
The news here is: cereal has no real benefit for your baby. You may have a doctor who recognizes that or has at least read the La Leche League research about it.
Cereal is grain which humans weren't designed to digest - and the cereal you would give is fortified - which means it is given something artificially not there. It also means that what it is fortified with is partial vitamins, not whole ones. that's the part that isn't spelled out for everyone.
You can just as easily give pureed or partially veggies as cereals, and they are far more healthy for your baby. Go with what your baby wants and likes first - and if rejection is the order of the day - try another week or month.
I went with my gut when my oldest refused cereals - and should have had a clue when he still refused them without my milk added to them - but I hadn't met my La Leche League meeting until he was 14 months. but I didn't truly start him on solids until 8.5 months, and at that, most people would have called it 9.5 months since I was giving him so *little*.
As far as sleeping through the night - babies weren't designed for it. That's another thing I've learned (and has sustained me through my second son's voracious appetite! ; ) So trying to create where design wasn't meant, may lead you and your baby to frustration or more.
Exclusive breastfeeding until your baby is one year old may not be on your plan - but it may be your baby's! It still doesn't mean you have to but it may mean you have more true *peace*, nighttime or otherwise. I fed my youngest exclusively for almost a year (not counting older brother's attempt to feed him what HE was eating ; ) and he didn't miss out on anything, weight-wise or food.
I encourage you to find a la Leche meeting near you and voice your concerns, and hear what they have to say. You can contact a leader if there is no meeting close to you.
Also, Dr. Jack Newman has a site with a ton of information on breastfeeding you might want to read more from:
http://breastfeedingonline.com/newman.shtml
Good luck, and great work looking out for your baby!
M.
PS: enjoy the 'clean' diapers while you can! Solids really change things.