Unsolicited advice: Strength training is amazing for posture and back problems. I know squats can be intimidating but once you get them down it helps your over all body including your back. I know you do yoga right? That plus weightlifting is an amazing combo!
My husband had the worst posture and constant back problems, but ever since we started weightlifting he has minimal complaints and is standing up straight. Also zero drop shoes if your feet can handle it. Wide toe boxes also improve posture because your feet are the actual start to all problems. That and sitting at a computer for way too long.
I thought it might help to mention this stuff.