So I know that this might sound really stupid, but here me out. For the past 12 months I have had an unlimited like proper unlimited data sim in a 4G modem, which I connected to my houses network. Bam internet. But last week I got a letter from my ISP saying that if I don't move the sim from the modem into a phone by 21 October then they'll deactivate the sim. Bam no internet.
So my idea is, Put the sim in an old phone I've got lying around, connect that using a USB cable to a computer, therefore hot spotting the computer from the phone. Then somehow using that computer as basically a router and distributing internet to the rest of my house via that.
Unfortunately the only spare computer I have that could do this is a Raspberry Pi 3B+. I've already gone online and looked at some guides on how to set it up as a DHCP server but none of them work.
Please Help