Flat earth is not only scriptural, it is also founded in Tradition, plus the Church specifically condemned Heliocentrism, all proving this is a matter of Faith. Besides that, the round ball Heliocentric model is masterminded, controlled and promoted by freemasonic demon worshiping liars raking in billions with all the associated lies: NASA fake space exploration, moon landings, evolution, global warming, the Big Bang science garbage and the notion resources are scarce which assists in bringing about eugenics, abortion and population control. They say lies enslave and this one is a whopper, so there's no question it matters to the Faith which is the answer for all our ills. If only we believe.
FE is scriptural in the sense that you are looking at Scripture, but you are not understanding Scripture as the Church teaches us to, but rather as heretics do. FE is founded in Tradition in the sense that you are looking at the writings of the Fathers, but you are not understanding them as the Church teaches us to. The condemnation of heliocentrism does not say anything about the earth being flat so it does not prove anything about it.
You are at liberty to believe the earth is flat if that is what you think the science shows, but there is no basis for claiming that it is a matter of Faith. It is simply untrue to say that FE is a Catholic position. One needs to directly contravene explicit magisterial teaching to have reached the conclusions that you have.
There have been some very evil ideas introduced by the "Enlightenment" and, as I understand it, it is reasonable to associate Freemasons with promoting them. You are right to stand against such ideas. The shape of the earth, however, is not one of them. Rather, the falsehood that we ought to fight is that science and reason are opposed to the Faith. As part of this falsehood, they have spread the myth that FE is a Catholic belief. If you wish to battle "freemasonic liars" you need to recognize that this is one of the lies.
I understand that it is difficult to accept a new idea when you have become so accustomed the old one. You have probably never seen
Prudentissimus Deus before I cited it. You probably need some time to read it over and think about it. Perhaps you know a trusted priest you could discuss this with. I am sure that you did not intend to go against Church teaching, but now that it has been pointed out to you, you have an obligation to conform your mind to the mind of the Church. You can continue believing the earth is flat if you would like, but you must stop interpreting Scripture and the Fathers contrary to the way the Church teaches us to.