Affiliate Marketing Secrets

Are your stories mostly about you in fantasy lives or do you write mostly about what you think would work commercially. I mostly write what interests me which is mostly romance or sci fi usually combined. But I get that it could have a small niche market if I wanted to sell one of my finished books. I’m usually the main character Somtimes I use my real name sometimes I give myself another.
Is it better to use made up characters? Do you know of any writers who openly admit to writing themselves into their stories?

Is being a good fiction writer like being a good singer? Like you’re either born with crazy imagination or you’re not? I’m not a very good writer(I’ve been told so by good writers that this is so) and it just feels like I can’t wrap my head around how to write what I see on the paper and I can’t tell if what I’m writing sucks, and I’m bad at putting words in the right order so it doesn’t sound smooth.