What's going on 😔

I have flu like symptoms but no fever. I have horrible pains in my back in the exact same spot that I had pains when I was pregnant. I have random horrible "cramps" but no sign of my period. (My periods are very light and usually painless) The pains come and go throughout the day at random times. I get horrible headaches when I sit up or stand. If I stand for too long my back goes numb. (Tmi I've had diarhrea for the past 4 days) I have never felt this horrible. But like I can move around and walk and do things and be ok.