An underlying premise of FCC is that you don’t need a special aptitude or innate ability to learn how to program. Anyone can learn to code. How far you get and how successful you are isn’t a matter of aptitude, but of interest. You have to enjoy solving certain types of problems. You have to want the challenge of going off into uncharted waters. What stops people from progressing on their journey isn’t that they don’t have the tools to continue further; it’s that they no longer consider it to be worth the amount of work that it requires.
In terms of “warning” people, I think that you’ll find the community here to be very honest about the fact that learning to code is hard. One of @QuincyLarson’s most linked articles on the forum and in the chat is One Does Not Simply Learn To Code.
I’m sorry that you’re feeling frustrated. I know with absolute conviction that you have the ability to succeed at this. The question is, do you have the drive?