You "don't believe in fact"?
Does that mean you deny all knowledge, and are basically living a Descartian world, where the only thing you accept as truth/fact is that you exist?
So when you exit your second story flat, you're as likely to do it via the window as the door?
Or perhaps you deny the existence of the wall and just go straight through that?
I know I'm trolling right here, but I'm trying to make a point.
It seems to me, that you're asserting that if science doesn't learn the absolute truth, it is worthless.
That is wrong.
All knowledge we have, is empirical. Our view of the world, is not the actual world, but the world as perceived through our senses, which we know deceive us all the time.
We need something else than our fallible senses, perceptions and preconceptions to understand the world.
Science, and the methods surrounding that idea, is simply our best way of gaining knowledge, and has been for hundreds of years.
When new evidence comes to light, science adjusts its views. That is how knowledge evolves.
Thus, "facts" as you state (by which I think you actually mean "knowledge in general"), are not absolute, and what we "knew" earlier may be different today.
And there are differences between facts (e.g. the sum of degrees in all three corners of a triangle is 180) and theories (e.g. the theory of gravity).
Facts in themselves are not man made, they are merely discovered by us.
I don't think there are too many actual facts known, outside the sciences of math and maybe physics.
The remainder of our knowledge is based largely on theories.
Theories are merely models of how we think the world works. The difference between a scientific theory and how we use the term "theory" in everyday life, is (among other things, I'm sure) that a scientific theory is testable and disprovable. The fact that it is disprovable, gives us reason to trust its validity, because after many tests of a given theory, if it still hasn't been disproven, the likelyhood of it being true, grows. Strong, well-proven theories, become foundations for new theories, and our system of knowledge grows. Some theories are so well-proven and interconnected with other theories, that we simply accept them as facts. That does not mean they are facts.
A short, but imperfect example is Newton's theory of gravity. This theory works well for most applications, and as such is a useful model in many cases. There are, however, cases (such as when doing calculations on star-size gravity-fields), where you instead have to use Einstein's theory of relativity in order to get more accurate answers. This does not mean Newton was completely wrong, or that his theory is somehow worthless.
Yes, it's incredibly naïve to think that what we "know" today, is the absolute truth. Actually, we know that it most likely isn't the absolute truth.
Whether or not it is a good enough approximation (or model) of the truth is a rather more interesting question.
That is; can we live with the mistakes and miscalculations we undoubtedly are making every day?
For my part, the answer is unequivocally yes.
Science is a difficult concept to fathom, but in all honesty, I can't think of any better approach to learning truths.
If I may offer you some advice: You'd do well (as would many, many others) to learn a bit about the foundations of science, and the philosophy of science. The people who made the foundations of science, were largely philosophers, searching for a means to learn "the truth." It is a subject which I myself found immensely interesting and rewarding to learn about.