Your t and z scores are suggestive of low bmd i.e. Osteopenic in simpler terms your bones are weak but not brittle. Consult your physician for taking
calcium and vit.D if not already taking . I also do suggest to include exposure to sunlight to your daily routine in early morning for just 5-7 minutes make sure you get in sun before 7 am depending upon location low heat sun rays.
Next Steps
For back pain you can start with doing bridging exercise to strengthen your back muscles and carry with your normal day schedule. Research shows that exercise and supplements mixed together gives better results as compared to following any 1 regime
Health Tips
Be cautious not to fall as your bones are weak and gradually increase the intensity of your workout start with 5 repetitions , then 7 , then 10 so on.... and dont be in sun for long as you may get sun burn , when in sun avoid applying sunscreen and sitting in sun behind glass window / shield . For further relief consult nearby physio / telerehab service provider. Stay healthy