My best friend does the cleanse with me every 6 months and she used to get that same rash on her face. More at the beginning and less as she continues to do the cleanse.
Also, I'm 5'5 and started at 142. I'm on day 7 and have lost 9 pounds. Sometimes I lose more when I walk daily. I think it's different for everyone and doesn't really depend on how much you were when you started. Try to stay active during this though.