So because people disagree and it's annoying, nobody can actually be right?
Think about it this way: For all the denominations that have turned Christianity into a joke (and I agree that they have), if it hadn't been for the Protestant movement, which was in its time entirely confined to the Western/Latin/Roman Church, there would be essentially four main forms of Christianity: Chalcedonian Orthodox, Chalcedonian Latins, non-Chalcedonian Orthodox, and Nestorians. So if you discount the possibility of Protestantism or any particular Protestant sect being right (which it would make sense to do, as if it were otherwise that would mean that the other 34,999 or however many sects founded upon essentially the same operating principle and with the same authority as the right one
are nevertheless somehow wrong), you can at least get back to a reasonable number of choices. You can be Latin, you can be Eastern Orthodox, you can be Oriental Orthodox, or you can be Nestorian (assuming they take converts these days and you can actually find a church/are outside of Chicago, IL). That's kind of it, as far as Christianity is concerned.
And yes, they do teach to varying degrees some conflicting doctrines. If they didn't, there'd be even fewer choices that you'd have to make. But this is where your own inquiries, powers of deduction, etc. come in and you can deal with individual claims separate from the loudness of the people making them. It strikes me that there are an awful lot of people in the same situation as the OP, who not only desire to find the "right" church, but also desire that this church be somehow demonstrably right with such obvious force that any counterclaim is immediately annihilated and thrown into some kind of alternate dimension where nobody can ever mention it again. Sadly, that's not how things work. Most "new" religions or sects are nothing but old heresies in new packages: Many evangelical sects embrace things like Chiliasm and a kind of reworked Montanism; Islam is what you get when Judaizing sects like the Ebionites and Arianism have a baby; modern Roman Catholicism takes the "intellectualism as theology" idea of Barlaam of Calabria and runs with it; etc. These things don't simply go away.
So, unfortunately, the noise will always be there. There was never a time in the history of Christianity (or, indeed, of all religion) when it wasn't there. If there is any religious group in which such dissent or contradiction is not possible, that's
the one you really want to stay away from, because it's very likely quite dangerous. But in Orthodoxy at least, there are things that are essentials on which we are agreed (they may vary based on the communion you find yourself in, but each communion has their own set: 3 councils, 7 councils, etc.), and then there is everything else, in which you are likely to not find agreement among people who are otherwise agreed in the essentials. That's just life. I am sorry that the OP has gotten tangled up in such things. It is understandable, but not really necessary. We work out our own salvation with fear and trembling, and there are no shortcuts.