Hi Camille,
I have do similar work and have been doing for over 20 years. I have found that adding some weight training has helped a lot with any back pain or soreness. Along with exercising other parts of my body, I do these to strengthen my back:
https://exrx.net/WeightExercises/GluteusMaximus/BBDeadlift (Don't go heavy at first)
https://exrx.net/WeightExercises/BackGeneral/DBBentOverRow
https://exrx.net/WeightExercises/LatissimusDorsi/BWPullup
https://exrx.net/WeightExercises/E***torSpinae/WtBackExtension
and some abominal work like crunches.
I have found that as my body strengthened, my posture and pain and soreness improved.
Along with this some active exercising like walking, jogging or biking also helps.
Some stretches that may help:
https://exrx.net/Stretches/E***torSpinae/Lying
https://exrx.net/Stretches/RectusAbdominis/Kneeling
https://exrx.net/Stretches/E***torSpinae/Cat
Some supplements that may help are Taurine, Vitamin C, Vitamn D3 and Glucosamine W/Tumeric.
Hopefully, this helps give you some ideas. I'm sure there are others on here that have good ideas also.