Dude, calm down.

I wasn't trying to be condescending. If a technician has looked into it then I guess there isn't much you can do. The issue usually not coming from copper cables was just supposed to maybe give you other ideas on where to look for an error. Like, maybe your router sharing its WiFi frequency with too many neighbours or something.

Also, I'm not saying you should spend more money on mobile. I just don't think the pricing is as bad as it was ten years or so ago... Getting mobile broadband for 20 bucks is cheaper than most landlines and if the reception is decent it might be an alternative. If it isn't for you that's fair, too.

If LibreOffice isn't an alternative then maybe try to run your office in wine? For things that aren't games the setup is usually manageable. If that doesn't work then maybe a VM might be a solution? I think most modern VMs offer modes where they keep the boot process of the guest OS hidden and just show you a single window. Like, you get an office icon on your desktop in Linux and if you click it the system boots a windows wm that directly launches an office window but only shows you this window once it's there, which should seamlessly integrate into your Linux desktop. If you're a student I think there are cheap or free ways for you to get a windows license to try this, but it's been some time since I studied so don't take my word on this.