Lower back pain

Am

I am currently on day 8 of lower back pain. My period is supposed to come in 13 days and I don’t know what to do. If I go to the er they won’t help me with anything but keeping me there for 12 hours to do nothing. The pain is so bad it feels like my period cramps just in my lower back and thighs. It’s to the point I’m having trouble walking. Does anybody have any tips to relieve the pain?