The trick about science is that we refine knowledge. Let's talk about matter. Way back when, people basically thought stuff was stuff. There was no logic to it, so they broke it into four elements. Eventually it was refined - no, it's not four. No, fire isn't an element. Look, we can split this substance out of this compound and it burns like hell! Eventually we figured out that matter is made of many, many elements. Oxygen and nitrogen and carbon and hydrogen and so many others. We said they were made of atoms. The word literally means "indivisible." The world they understood said that atoms were the smallest thing! But again, we refined. There were mysteries that we pried at until we figured out the next thing - atoms could be split! There were electrons and neutrons and protons. And we fiddled and we pried and we figured out that these particles could be broken down! Quarks dancing to a probabalistic tune that hurts to even think about.
Do you see what's happening here? Even if we figure out that our theories about quarks are wrong, it's not going to blow up the theories that depend on electrons and protons and neutrons. Each time we make a new theory, we are refining the old ones. The changes become smaller and more focused.
Sometimes something comes completely out of left field and rewrites a branch of science. But you can't base your life around such a thing happening. You just accept that you might be wrong about a few things so that you can be mostly right about a lot of things. It's better than using no logic at all and being wrong about pretty much everything.
You say you doubt the Big Bang and that's great because "it's just a working theory." If something comes along to re-write that theory, it's not going to make the universe 6000 years old for you. It'll be something small, something that fascinates mathematicians and is completely impenetrable to the rest of us.