Breastfeed 6wks old. During a daytime I hardly have letdowns and have low milk supply. At night when sleeping have oversupply and plenty of letdown. Why?

Breast feeding. Quantity mainly depends on the baby's sucking patterns. You may be more relaxed at night when sleeping. There are medications that can help with milk product. Drink lots of fluids and in courage your baby to breast through the day. All the best.