If you're like me, these types of thoughts routinely run through your mind. I think it applies to most writers, and creative types in general. These types of thoughts will stop your writing and creative goals dead. So banish or execute them as needed. They only serve to hold you up (and likely aren't true).
I suck/this sucks (You don't. Everyone starts somewhere, and you can improve your craft through study and practice).
No one will want to read this. (There are billions of people in the world. Do you honestly think no one at all will like it?)
No one will publish this. (Send it out anyway. We're not the best judges of our own work. If your work gets rejected, send it again. Repeat as needed.)
I'm a fraud. (Everyone feels this way. Keep going.)
No one will buy this. (See No one will want to read this.)
My parents/friends/partner told me I shouldn't do this. (If the people around you constantly crap on your goals/dreams, you may want to re-evaluate the relationship.)
I'll never achieve success. (The most successful people in the world started from nothing.)
Everyone else is more successful than me. (Comparison is deadly. Put in the work. Keep going. Keep learning and improving.)