BAby Is 5 Months Old C Section , Bleeding Started

BAby is 5 months old c section , bleeding started when baby was 4 months after excercise , had 2 corses of northistlone and when I stop the corse the periods are really really heavy and fresh blood not tailing off ! Been treated for infection in my wond but still as bad ! To put a tampon in is really painfull ! Changing pads every hour ! Please help