Earlier quoted context omitted.
Why not just use the hotspot on your phone?
I believe that you can't both simultaneously provide wifi hotspot and use wifi internet (at least, I couldn't on a phone several years ago last time I tried it). I think you can only do that if the network the phone is using is accessed via the cellular modem.
These days you can passthru your WiFi or even a wired connection (via USB to a connected PC or a Ethernet-to-USB adapter) via a Hotspot.