I think I pulled a major muscle in my back. ?

Ok so im a 25 year old female. I just started working out a month ago. I didn't really stretch my back like I should last week, got on this machine that helped with your lower back muscles. I remember feeling a bit of pain during that exercise. Well, my left side of my spine has been hurting sooooo bad on and off since that happened. It really hasn't let up after over a weeks time. The pain starts midways and works it way all the way down into my hip. It almost feels like its under my hip bone and goes through my . The pain also stretches to my left leg! I'll be fine sometimes, and then it starts hurting out of nowhere for a few hours, goes away, comes back when I sit certain ways. I try to adjust how im sitting but the pain will stay. My right side is fine. I'm curious if any of you are muscle "experts" and might can tell through this description which muscle I pulled, If its pulled or tore,and what I should do (since i don't have health insurance, is there a way to alleviate the pain?) Thanks!