Oh no this is familiar to me. At around two to four months i noticed let down was alot and in hindsight i realised that baby was overfed and intestines were inflamed plus the colic! Could be baby throw up milk because its too much and tummy hurts so the struggling arching. Its a bad cycle where baby feeds and seek comfort in breastfeeding but adds on to the pain when over feed. That was what i experienced but im not sure if its the same case for u. Her stomach got better after four months and my supply was better regulated so no more colic and throw ups after that period!