Sudden spikes in Internet data usage

Hi

I am looking for an explanation on why my internet usage as explodes over the last month,  Our usage patterns have not changed in March I got the email/text that I was going over the 1.2TB limit but did not give it much attention as I figured it was an anomaly.  However on the the first day of the month April 1st xfinity indicated I had already exceeded my limit in 24 hours.  I have looked around my network equipment but again can't find anything that looks strange or excessive.  Ihave been Comcast customer for 15+ years and have never had an overage until now.  Can anyone provide guidance into what is going on?  I have seen some posts that indicate this is a xfinity issue but I doubt they will acknoweldge or provide credits for the overage.  See my usage stats below