Advice Needed. Just Got A Ransomware.

Dumb me. I was downloading some sorta a plugin which I needed so bad. Turns out it was injected with Ransomware, my Desktop files got encrypted. I tried to change the extension but it was already spreading. So, I cut off my internet connection and tried to change it again and that seemed to work. My hard drive folders is now fine. However, the virus is still in the system. I restored the windows using the recovery option in the hope of getting rid of the virus but, no, didn't work.

Now, I cleared the system but I can't install a new windows. Looked it up and found out that I should clear out the hard drive too.

These folders are 3 years of work projects I really can't afford to lose. It'll be a huge tragedy seriously.

So, any advice? Do I have any options?