J.S.
That same thing happened to me, almost exact except my baby had actually LOST weight at his 6 month check. The doctor told me to start supplementing which made me sick to my stomach. I ended up switching to formula, I was pretty much dried up. I also ended up being pregnant which may have been a factor. It can be SO hard, the whole nursing thing. I am starting to have problems now with my second (now 4 months old) and am getting nervous. I am actually heading to a La Leche League meeting tonight to see if I can get some help. I just wanted you to know that there are others out there, it is so hard not knowing what to do and so frustrating. Especially when you are on your 2nd (or 3rd) baby, aren't we supposed to be pros now? Anyway, hang in there. La Leche League can be pretty hardcore but at the same time they may be very helpful. www.llli.org.
Good luck!