Lower left back pain above the hip upwards

Hi everyone, I’m 25F and I’ve been dealing with lower left back pain since December. I hadn’t been going to the gym for a couple months when it started. It feels like a stabbing pain sometimes, and other times it’s more of a dull, heavy ache. Stretching seems to make it more inflamed and actually worse. I’ve been seeing a chiropractor and a physiotherapist twice a week for the past 4 weeks, but they still can’t figure out why it still hurts. They keep saying it seems like a normal muscle strain. The pain has started spreading to my side now. Standing for long periods hurts, sitting hurts, and lying on my back is actually the most painful. Has this happened to anyone?