How to make sense of so many conflicting theories and ideas in the field with an open mind? Is every school of economic thought as valid as the rest? 'm a junior economics major and lately I've been in a sort of crisis because I feel like I'm not sure what economic ideas I believe in anymore. Don't get me wrong, I love reading anything that has to do with the subject. Thing is, I just feel like, for somebody as skeptical as me, it's tough to remain convinced of anything I learn. I used to blindly agree to mainstream econ when I first started studying this, but then I was introduced to different schools like Marxism, the Austrian School, New Keynesianism etc. and it made me realize things are not as simple as I supposed they were. Now, however, I feel like I don't have the tools to discern what is good and bad economics. Sure, I know marxist theory or austrian theory are not exempt of criticisms, but neither is orthodox economics. And what's worse is that I feel I'm not capable of criticising them on my own: I always depend on somebody else's analysis of the state of modern economics, his/her interpretation of Marx and Von Mises, etc etc.; so I don't know how much to trust their opinions either.

And I look around me and it seems as if everybody I study with just CHOOSES what to believe in (Austrian/Keynesian/New Classical/etc) instead of deeply analyzing all theories and accepting what seems to be the most rational school of thought for them.

So in summary, what is there to do for me? It's like there's a counterpoint for every argument and I'm not capable of sorting out on my own which is more reasonable. Is there anything I could read to find out what different methodologies each school of thought uses, where exactly do they differ and how scientifically valid are their theories?

I'm not sure if I'm asking for too much, but I'd honestly appreciate any kind of response.
This is how I view it. At the very core of economics, is each and every human on this earth making decisions he or her thinks are in his or hers best interest. In real life, we do not calculate utility before making a decision or compute any expected values; we do what feels right at the moment.

Taking the cross-section of human decisions, economists try to make sense of it all, and ultimately deduce some theory that resembles a law of physics to shed light some basic insight into the human condition.

This is a mighty hard task; near impossible. Its amazing to me we've made any progress at all, yet here we are.

As a field of knowledge, economics will never explain the world perfectly in whole, because the nature of what we study is far from perfect and certainly stochastic. There will never be a unified theory of economics, but that does not mean the small pieces of insight each economics paper tries to uncover is trash. It is still valuable to use what the data can tell us, to the best of our ability, to guide our future decisions, and analyze the decisions we've made in the past. 

If anything, its interesting as hell.