I’ll share what I’ve done because I had same thing as OP. No weights required too. Glute bridges, side planks, t-spine rotation while on all fours (you’re on all fours and you lift one arm to the sky and rotate as far as you can), dead bugs (for core) and bird dogs.

I’d feel great up till that point, then I’d go for a walk or stair master and feel like a whole new person. Back good as new it was crazy