YES YOU CAN IF I DID IT SO CAN YOU
I'm like the biggest coward on the planet dude. I avoided posting on ao3 for YEARS. And I mean that literally. Actual years. And if there's one thing I've learned it's that there are millions of people on ao3 and someone is bound to like what you write no matter what. And even if they don't, whatever, fanfic is a self-indulgent concept, you should be writing for you anyway. Plus some people give great advice in the comments on ways to improve your writing. And even if you don't post on ao3 you can still write on like ms word or in your notes or something to yourself and just never post it. That's what I do mostly.