Well I am, by no means, a doctor/chiropractor/physical therapist but some things to help strengthen the lower back:
-good mornings help
Maybe try some glute-activation exercises as you're warming up:
-Double/Single-leg hip extensions (also known as glute bridges)
Also, it might help to make sure your torso is strong overall. So try to work in some ab/oblique exercises.
Again, I'm not a specialist with back injuries so I recommend seeking one out before you go and cause some more damage to your spine.