A good place to start is working on your posture and bracing some more. Try some deadbugs/breathing exercises where you keep your abs braced (especially your low abs below or next to your pubic bones) and work on breathing while braced. Best to do this on your back with legs lifted. Can you bring them down and back up while remaining braced and while controlling your breathing? If you can’t control your core while breathing this leaves your spine unprotected while lifting.
In terms of posture, make sure you pull your ribs down and keep your butt squeezed a bit and core tight to avoid overextending and making the problem worse. You could mobilize all day, but without fixing these basic human skills, things won’t get better for you.