This is only tangibly related to ‘what if my writing is bad' in that people have different definitions of crap. For example, did you know there's a constant debate about the quality of literary fiction versus genre fiction? And did you know those debates are always stupid? Because they are. They are always stupid. They are stupid because people always have different tastes, and what one person gets out of this year’s Depressing Best Seller, another will get out of that same exact thing, except it’s this year’s Depressing Best Seller With Vampires. People like different things, is what I’m saying. Some people want to read Jane Austen, and some people want to read Jane Austen fighting zombies. I am not saying those two things are equal! What I am saying is there are people who enjoy either or both of those things and that is perfectly okay.
What you want to write is not inherently stupid on the basis of what it is. Don’t let someone talk you out of writing your high school drama with werewolves. Don’t let someone make you feel bad about wanting to write about your childhood. Don’t listen to people who tell you your story ideas are boring, have been done, or aren’t worth the effort. Do you want to write them? If so, then they’re worth the effort.
Write what you want to write. Sometimes this is hard! Sometimes when you tell people about your story ideas, they tell you they’re not good. They’ll give you lots of reasons, like there are already stories like that, nobody wants to read stories about people of color, young adult novels are silly, you can’t have a gay main character, etc, etc. They will have lots of reasons. You don’t have to listen to any of these reasons. You will not be happy writing what other people want you to write instead of writing what you want to write.
That doesn’t mean thinking about what other people might want from your writing is a bad thing. It doesn’t mean there aren’t valid criticisms out there. It doesn’t mean you shouldn’t listen to those valid criticisms, even when it’s really painful to do so. But ‘you shouldn’t write about this’ - whether that this is a particular genre, a particular topic, or an event in your life - is not valid criticism. It’s bullshit. Don’t let that bullshit stop you from writing.