Internet Shutting Off Automatically (HDD Failing?)

Some mysterious stuff has started happening with my 2013 Macbook Pro these last few days.

First of all, my Spotlight isn't working anymore. No files are found when searching Spotlight, I have to use EasyFind instead for simple things like documents or mp3 files.

Second, my internet stops working every 15 minutes or so. The way to fix it is simply to shut off Wifi and re-connect to the router. Then it will work for another 15 minutes. There is no problem with my internet itself, as I have no trouble using it with my Android phone.

When I open up the disk utility and do a "see disc eligability" (? - I don't know how to translate it precisely, my OS is in Swedish) it shows a few errors like "bla bla bla should be 80, group is 0 etc. The errors do not fix by repairing disc eligabilities.

Are these problems related or is there something else going on? Getting worried that my hard drive will shut down as has happened so many times on past computers. But this is a flash drive so it shouldn't crash?

What is the problem? Thank you!