Running around the internet today (even using "safe" practices) without any AV is.... well, you deserve what you get (and you probably already got it, and you're spreading it around to others.)
Go to AV-test.org as suggested. Click on the Home User tab, then "Protection" in the right hand column to sort. Windows Defender comes in dead last- and has for years. You just think you're protected cause nothings happened.... that you know of.
I'd at least use Avast!. It's free, pretty good, fully automatic, and does not slow your machine down.
Personally, I use Bitdefender. I get a 'Monthly Security Report'. The last one said 46 files had been cleaned last month, even though I also practice "safe" computing. What does that tell you?