breast feed is no doubt the best feed for your baby.
exclusive breast feeding is recommended till 6 months of age.
weaning some says can be start from 4 to 6 months.
weight normally gets doubled by 6 month and triples by a year of the birth weight
you are right in satin that milk production and giving feed to your young one depends on the stress
so you really need to be relaxed and calm in order to be appropriate.
hope this helps.