Ever since i had my first daughter three years ago, i've had pain on the right, back side of my neck, lessens if shoulders are down?

Muscle compensation: It sounds like you have been compensating through your upper back, arms and neck since having your child (from holding her, daily child activities, postures etc). I would recommend seeing a physical therapist who can evaluate your posture, movement patterns, and muscle imbalances. From there he/she can provide treatment and give you a home program to help yourself.

Chronic trigger poin: Massage trigger point injection baby sling may help strengthen after pain goes away to avoid next one.