Business or hobby? If not, do I amend?

Last year, I received a 1099-misc in the amount of $800 for some freelance writing (which I do for fun). This was a little less than 1% of my overall income. I didn’t expect to do more of this this year (2020) so on turbo tax, I checked the box that stated, “I don’t expect to do this in 2020.” Well, it turns out, I’m now doing it in 2020 and it is about the same amount. Do I now have to file a schedule C? If so, so I have to amend my 2019 tax return and include a schedule c?