Not feeling well :(

For 4 days now I've felt like I'm fighting the most bipolar flu ever. I bounce back and forth between freezing and shivering to sweating like crazy, my bones ache, my muscles are all weak, my legs keep cramping, I've had a horrible migraine, and the thought of food makes me nauseous. When I gave birth 2 weeks ago I was diagnosed with a severe uterine infection, given ampicillin during labor, and I ended up giving birth 5 weeks early. After the baby came out, there was no follow up about the infection, so now my husband is afraid I might be moving towards sepsis. I'll call my OB Monday if I'm still feeling like this, but has anyone else had this and what did it turn out to be?