Girls, I'm having a panic attack? My lower back hurts since yesterday,…

Girls, I'm having a panic attack? My lower back hurts since yesterday, sometimes my abdomen also hurts. I can't sit or lie down for long, it gets better when I'm on my feet, but I can't walk all the time either, it's hard ? I have cramps, I can't understand what's going on? I'm afraid I might miss something?