Pulled muscle in lower back

I played volleyball last night and did something to my left side lower back. Sore stiffness down into my glute. Walking like an old man. Lots of stiffness and dull pain, especially when changing posture. It’s been about 24 hours and I am definitely feeling better, but it still hurts and it’s clear I did some damage. I’ve watched some YouTube videos for stretches and exercises I can do but thought I’d see if anyone here has had a similar injury or any advice.