You are right, it doesn't happen with any other O/S except iOS where you have to pay people/Apple to fix it (or reset the OS) or Windows where the stock response is "reinstall the O/S"
How valuable is the data on your laptop? Did you have it backed up? If so, stop worrying and just take the Windows approach. If not... Find someone local to you who is able to fix it (good luck with that...)
As for the rest - you come over as someone who expects someone else to fix your shit for free with no information other than "waaaa it's stopped working"
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Fwiw, based on your brief description of symptoms, I would say your boot device file system is broken somehow. To fix you need to mount it on another booted OS and fsck it (however if it mounts, copy valuable data off onto other media, then fsck it) . How to do that is left to your powers of Google. Not warranting my response in any way.
Best of luck.