This is a preliminary study on BAA (Breastfeeding aversion and agitation), that was done in 2015 and it found that there are quite a number of mothers who have this problem.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5684792/
It doesn’t give any solid conclusions, but it suggests that, from a biological viewpoint, BAA is nature’s way of encouraging weaning due to insufficient nutrients or hormonal imbalances. It suggests if a mother is not eating or sleeping well, and the baby is taking too many nutrients away from the mother, then she/her body is likely to have feelings of BAA to avoid nutritional loss.
I’d encourage you to read the study, because it also gives references to other studies you’d for sure find useful.
I’d also urge you to bring this up with a health professional (If you haven’t already), for they of course would be the most knowledgeable on the subject. Since BAA can raise cortisol hormones in the mother’s body which then get into the milk, it’s doubly important to get a professionals recommendation.
I’m very sorry you’re going through this, and hopefully there is someone on here who’s experienced it firsthand who can help you out more.