Expensive lessons here and I do hope that many members here will learn from the OP experience and not repeat the mistakes of using public wifi or cloud storage to hide your sensitive data.
You're wrong, it's totally safe to use a public Wi-Fi, I will give you a link about a video regarding the true stuff behind the protection offered by almost any VPNs in the market, it's a short one so it's not that tiring to watch.
https://youtu.be/WVDQEoe6ZWY