The dynamics of breast milk production is such that milk is produced by virtue of the stimulating effect of the child's suckling on its mother's nipples triggering a "letdown reflex" which delivers breast milk produced "de novo" [a new] directly to the breast ducts and into the baby's mouth [contrary to the popular belief that the bulk of breast milk is "stored" in the breast].
You need to relax and not to worry as it would negatively affect breast milk production. You also need to eat well and drink lots of water.
Breastfeeding is demand and supply. The more you put the baby to breast, the more the milk flows.