lie facedown with the top half of your body on something high enough that your feet don't touch the ground and do reverse hyperextensions
do it for multiple sets of 20+ reps
don't just swing your legs and drop them down either, really squeeze your back muscles at the top
do back-bridges, hold them for 30s
look at your posture in the mirror, make sure you don't have lumbar lordosis/anterior pelvic tilt, if you do there is a million yt videos about how to fix it
hang from a bar, do it for multiple sets for as long as you can, ideally the bar will be high enough for you to keep your legs down without touching the ground, this will help decompress your spine (and joints) and give your muscles a nice stretch
look up a follow-along full body stretching routine on yt and try to do it most days, they're usually only 10-15 mins so you can just do them before bed or first thing after getting up
do one or all of these, make sure to be consistent and patient, it wont just go away after doing it once and stay gone forever
also have sex with brown girls
