Interesting. I experience those hopeless feelings, but not linked to breastfeeding. In the early days I would have strong sleepiness and thirst. All throughout my life intense feelings of elation were associated with thirst for me, and I once wondered if it was significant that anti-depressants lead to dry mouth, but I didn't get euphoria with breastfeeding thirst.
Nursing an older child, latching on has sometimes produced intense feelings of panic, feeling entrapped and needing to fight my way out. I would induce muscle cramps or invoke a sensation elsewhere in my body to help calm that response. Or sometimes I'd just end the nursing session. But I imagine that is unrelated as well.
Are the depressive episodes while nursing worse at certain times of the day for those of you who experience them?
Mine is worse in the early/late evening, before I go to bed but when my nursling is going to sleeping, or sleeping.