Hi T.,
Since I decided to breastfeed, I have looked and listened and learned that EVERYONE has a different version of what is normal and acceptable. Please listen to yourself and your baby first.
My son has a hard time with new foods. I follow the suggestion to nurse him first, then feed him.
Are you introducing them 1 new food at a time, 3 days each?
If you are nursing, he isn't starving. Nursing him will not hurt him - it will give him nourishment.
Are you giving him fruits also?
I started losing my milk because my son wasn't nursing enough - I cut back on solids and increased his nursing time during the day. He was 'full', so he just wasn't 'asking' me for it.
We have a much better situation now; he nurses, then eats, then nurses again. He usually eats 2T cereal at each meal (but at 8 months, he was at 1T) mixed with breast milk. I give him an ounce of veggie, ounce of fruit, and if he is still looking for something, another ounce of either (or now, Cheerios are an option).
I don't see the need to differentiate at such a young age the difference between eating and nursing. To him, they are one and the same - different sources for different foods.
Also, I didn't push solids until he was willing to eat them without screaming. So while we introduced him to rice at 6.5 months - he wasn't ready. (Poor guy tried to back up from his lips!) We tried again at 7 months, then 7.5 he started accepting the cereals. We moved up a little at a time. He is the one who knows what his tummy is ready for! The taste buds will follow.
Friends told me I am shorting him - but he is happy, and he is not losing weight. (he's not gaining either, but the ped'n for the first time in his year on earth is not worried about it, because he is MUCH more mobile now!) Friends also tell me that I am going to short him on his birthday by NOT giving him cake. I don't believe so. He will have plenty of birthdays with sweets and cake and ice cream - he doesn't need them now.
As far as a cup, I haven't found a BPA-free sippy, so I have been teaching him to drink from my glass. He is much more receptive to this than the sippy we had (he'd chew it and empty it), and cups he can hold aren't ones I want him to have (he loves to chew stuff now that he is teething, so plastic really is out for him.)
Go with what your baby is leaning towards. He isn't telling you to stop solids. He's just telling you he wants to nurse. That is normal and okay.
Good luck!
M.