ive had this before, and its gonna sound really stupid, but it could be trapped wind. i used to wake up bawling my eyes out because it felt like my back was gonna explode, it really hurt!! u could try getting hubby to smack ur back, like winding a baby, but be very firm! as much as u can stand. if it feels like it could help, then its wind. if not, get checked hun.
i mean, it might not be this, but its worth a shot!? xx