Data dam broke. Help

First, 12+ year user of Hughes.  Upgraded to Gen4 a year or two back.  Typically, service is fine.  We have 4 possible devices to use internet, desktop, laptop, and 2 phones.  Had some problems with usage when the wife got her new Iphone, but we fixed that.  Both phones stay off wireless.  

Last month (Nov) was fine.  we have 14Gb available for typical use, and we  had 3gb left at the end of the month.  Last night, wife told me the meter showed 0 allowance left, and we were on token gb's.  So, in 3 days, we went through 14gb's, and I watched another 2gb's go out the window last night.  I shut down the modem.  Turned it on this morning, and lost another 2gb's this morning.  Down to about 12gb's on token allowance.  Shut modem off again, and now working on Verizon phone hotspot, (which is spotty at best, I am VERY rural up here)

So, I do not belive the problem is Hughes based.  Aside from the Iphone issue, we have never gone over.  I think we got something bad, file wise.  

Here is what has changed in the last few days, since before we noticed the drain.  Desktop, somehow (wife's computer) had firewall and virus protection turned off.  I turned those on last night, and did a scan.  Firewall Defender reported wanting to block a program called Amazon Music Helper.  I agreed.  

I was fiddling with the Epson Wireless Printer, as I could not print from my laptop via wireless.  I got it to start printing.  I had to fiddle with the settings.  Not sure if I could have possibly done something to start it to be a drain. (I read somewhere on here, searching for solutions, that printers can cause a problem)

I am downloading (or trying to) Glasswire to try to track usage.  I will also download maleware bytes and run that (not sure why it isn't on my computers, it usually is)

Again, there is no drain if the modem is shut off.  It IS on my end.  Any other advice, things to start looking at?