retaining water, bloating....why?!

Im 8 weeks postpartum and have been retaining water in my face. Im so puffy its disgusting. Im also staying bloated. Like I look pregnant again! My belly had gone down quickly, it was flat (well flat for me) at 2the weeks postpartum. ) its been progressively getting worse for about five weeks now. Could it be because I've been on antibiotics for various things? I had a bladder infection, sinusitis, mastitis, and post partum preeclampsia. Idk what to think. My doctor isn't concerned. I've not gained weight. As a matter of fact, im 35 lbs lighter than I was before my pregnancy, and 25 lighter than when I delivered.