You seem to be very strong down the nihilism philosophy. I have a view point that nihilism isn't a useful philosophy & doesn't yield any particularly meaningful insights that help you find success in this world. It's very much, at least to me, of the same vein as the Omphalos hypothesis
(also known as Last Thursdayism by atheists such as myself) which says "Sure sure. You've got all these fancy theories. But how do you *know* the universe wasn't created in its current state Last Thursday & so all your measurements are meaningless?".

Worrying about an epistemological definition of "truth" that is different from the scientifically one is equally unhelpful. Scientific philosophy & the inquiry stemming from that actually yields results in any field you look into & just building on that. Worrying about a higher order definition of truth and certainty that only exists in your own mind (since no two people will agree) is irrelevant & unhelpful. Medicine has come a very long way from where it was & our understanding of it is drastically better than it was. Is it perfect? No. Is it infallible? No. Does it matter? Not really because at the end of the day it's infinitely better than where we started & continuing along this path will continue to yield results over time.

> In fact Newtons laws of motion is the perfect example. It was the ultimate example of scientific verification. All experiments pointed to the theory being completely accurate, to disbelieve the science was to disbelieve reality. It was at the time equivalent to disbelieving evolution.

I'm always fascinated by people who claim that Einstein's theory of relativity somehow undermines the bedrock of scientific inquiry when it's 100% the thing that supports it. Newton's theories weren't wrong. They were 100% correct for the environments we were testing them in. Like the all the equations behind the theory of relativity, if you turn down the speed & mass variables to every day human values, they literally turn into the same classical Newtonian mechanics equations. The *only* instance that you should be questioning the scientific validity of a field is when there's competing theories & the experiments themselves don't really help make decisions. Like dietary science. That's a field that constantly produces contradicting results. There's definitely some good advice but it's mostly hokum except for the parts that actually intersect with medical research or have really wide studies done because of the problems of limited observations. Same with pop psychology & other human-centered inquiries that don't have external sensors against which to measure results & large sample sizes to deal with the variation. Non-physical inquiries suffer very few of these problems & are easier to experiment with.

If it helps you, the scientific method of inquiry of in some ways is directly supported as a fundamental tenet of mathematics (via the fields of probability/calculus). If you sample an underlying distribution enough times with a random enough sample (no bias that's causing you to overlook things), the more the samples match your estimate of the distribution, the less likely it is that your estimate and reality diverge. That resolves, at least for me, the philosophical conundrum of "what is truth" and "have you really done enough measurements". For religious arguments, your form of argument is "the God of the gaps" or "God of the cracks". If you just focus on a crack, all you can see is all that empty space & not the bridge that the crack is a non-critical part of. Even science's philosophy is underpinned by a mathematical truth & our challenges sticking to it are our own failures, not those of science. I recognize this sounds like religion, but the difference is:
* Falsifiability. Good scientists will very quickly discourage any attempt at scientific inquiry of anything that can't be disproven through experimentation.
* Free sharing of knowledge. We're not as great here because of the economic realities of our society, but certainly better than religion organizations that tend to have more of their documentation in private vaults. That being said, this is the most fair point of criticism against scientific inquiry for me & the one where today's scientific industry gets closest to religion.
* Consistency of conclusions. It doesn't matter if a discovery fails to take hold. Over time the same thing gets rediscovered eventually. Like Calculus being simultaneously invented by Newton & Leibniz. Good ideas just have their time & inevitability comes from a build up of knowledge. Religions don't really share this property. Neither does philosophy which just has a bunch of models & no way to model/investigate them. Philosophy is useful as a hypothesis generation machine or maybe as a way to examine how humans can improve the scientific field. That's about it & we need to be quick to discard it when science starts providing answers.
* Belief or lack of it doesn't matter. Science is about making predictions. If the predictions are based on faulty science, they'll not hold up over time. If the predictions do hold up, then they're more likely to be right. Probability is where this gets tricky, especially so when polling human sentiments. That is walking a razor's edge.

Still, science is the only philosophy that's actually yielded tangible results consistently over any period of time. Religion & other philosophies have not.