Everything you write will be bad. That's a certainty. But there are degrees of bad writing.
Still, if you take time to prepare and document yourself, your work will suck a little less.
Use some kind of grammar check, at least cover your shame that way. Most new writers have glaring grammar errors, due to insufficient education or other more medical reasons.
Whatever characters you write, give them each at least three flaws. Of course, real humans have hundreds, but let's be realistic. You'll never be able to write a lovable character if you allow it more than three flaws.
Whatever story plot you have, add in at least one plot hole. There will be more, but at least this one you'll know about it.
Never ever write in 2nd person.Telling your readers directly: "You are a hero, go chop wood and make soup. Then dig a latrine!" It doesn't go well. Sure, in life you did suffer such humiliations, but as a reader you want to relax and be entertained, not be ordered around by some illiterate fanfic writer.
Post what you've written on multiple sites. Maybe under different pen names, if you can.
Keep in mind that moderators and literary critics on the internet are worse people than anyone you know. They will harass you, ban you, delete your works or your avatar, for whatever reason they want.
They have power over you, and they will prove it. Maybe your works are illegal in their country or religion. Maybe they are just asshholes or high on power. Be prepared to be censored and abused.
Still. There is Hope. Giordano Bruno was burned at the stake for his works. You will be fine.