Definitely sounds like a virus.
If it was me I think at this point I would take it to a good tech and get them to fix it, especially if you have important stuff on it such as music files. Pretty hard to do much at your end if you can't access the internet (except for this site?! How strange is that?)

Thing that bothers me is that whatever happened also disabled your malwarebytes, which is also the virus checker I use.