I don't use my personal Hotspot very often, maybe 3xs a year. The last two times, I consumed 15GB in one hour. How does Verizon measure usage. I believe this to be almost impossible. My phone only had one bar of service. I had a work laptop connected and was only checking email and visiting work websites and SharePoint. In one hour I received a text from verizon I had only 10% of my 15gb left. My son was on his phone and he had the same issue. My wife was streaming video and she had the same issue. All told each of us had 15gb each and we all burned thru it in an hour. We were camping in the nearby mountains. Every time I use my personal hotspot, I have this issue.
We always want you to understand your usage fully. There are many factors that can go into your data usage. First, is what you are using data on: emails, social media, videos, music, etc. These all will use different amounts of data. Secondly, how you are streaming things like videos. Is it in HD? Lastly, how many devices are connected to your hotspot?