Consider making the 5 Tibetan Rites for Immortality a daily practice. Those 5 sets of 20 movements can be done anywhere with no equipment in 7-10 minutes. They're designed as self mobilization techniques for the hips, shoulders, neck, and waist.

https://youtu.be/j_bY6REpIPE?si=XoK_apHZWYTXFmQ_

They will help your neck & shoulders deal with the postural challenges of breastfeeding, as well as the consequences on your back/hips from pregnancy and delivery. This suggestion is based on having been a professional massage therapist married to a Pilates teacher thru two pregnancies, as a wounded healer/athlete/martial artist myself.

The principal to keep in mind, no matter the issue, is that healing occurs most effectively through small consistent therapeutic stress/movement under light resistance through full range of motion.

Good luck and remember to enjoy both the peaks and valleys of your journeys.