Lol! "We will fight it because it frightens you." 

You say that, but I'm about 10 hours in or so and I'm getting absolutely reamed on normal difficulty. 

I lost more to some random miniboss troll thing than I did to Ornstein and Smough. I died more to some trio of beasts that came out of a dimensional rift (not even a miniboss, just a set of three enemies) than I did on Manus, Orphan of Kos, and Nameless King combined. 

I am getting the distinct impression I'm doing something wrong, because I'm usually pretty good at this type of game and it seems like every enemy is killing me in 1-3 hits, and it takes me something like 50 hits to kill them. I've been levelling up my strength and defense, I've been buying armor and upgrades and the like, but I swear I'm either doing something wrong or the game is doing a poor job guiding me in the right direction. It's actually getting remarkably frustrating. 

Example: After going around the first 'open world' area (I don't know how to use spoiler tags so I'll keep it vague), I found a platform with a dimensional rift of sorts. when I triggered it, two enemies came out, each one with more health relative to my strength than the hardest of Dark Souls bosses, and they BOTH kill me with one hit. This isn't a secret area, it's not hidden in the depths of the world, it's literally just off to the side of the main quest line in an area of the game when you have the option to explore for the first time. It's not even, like, the first enemy in front of a while area of the game, because if it was I could understand it being a deterrent to an area that's simply beyond my level. 

I just don't get it, almost every enemy is like this. when I watch JackSepticEye play it, that glorious man is perfectly parrying, dodging with ease, killing in a few hits, and not having the slightest of problems. I do the same thing, and get my tits rocked. It's bullshit. 

What am I doing wrong here? What am I missing? I don't want to hate the game, but it's more frustrating than even the hardest of souls-likes without any of the rewarding payoff.

Difficulty is definitely getting a whole lot smoother for me. At first I was getting completely destroyed, but my last couple hour play session I think I only died about twice. I really like melee combat, which given this is a GoW game which were previously all about the weapons, is really shocking to me. The shield is WAY more useful than shields in video games almost ever are, and ditto about Atreus. Spartan Rage really is great in a pinch too. Saving it for the really tough fights has helped me a lot.

As for the game impressions overall so far, it really does feel like a masterpiece unfolding the more I keep playing. The gameplay is starting to get a ton of fun now that I'm getting the hang of it and the spectacle in this game is  just jaw dropping, and I'm still pretty early in. If it keeps ramping up throughout, I can't even imagine. I love Atreus as a character so far and Kratos is already a more realized character than in the past. Really like their dynamic so far. 

GOW 4 is still more combo button masher while the souls games are slower paced space tactical.  The souls games gain their fame over their difficulty, crazy word and obscure lore.  The play styles between GOW 4 and the Souls game only share difficulty and the camera.  After that nothing about the are the same.  I would definitely say if you like this type of fighting game they give the Souls game a try.  They are fun, difficult and have their own style that is worth exploring.

You should be leveling up Arteus more than yourself.  He makes the difference in handling groups of different type of monsters with his ability to distract and interrupt their attacks.  You find the most annoying guy or flying shooting creature have Arteus lay down fire to interrupt their attacks then work on clearing the easy guys.  For the heavy's, getting Atreus up a level where he chokes them out and then shoot them to knock them down allows you to lay into them with some high damage combo.  I am playing at the hardest difficulty and this is how I manage staying alive since you can only take but so much punishment.

Be careful of those rifts.  they usually have monsters that are a higher level then you and if all of their attacks are red, just leave them alone level up and combat when you are ready.  Getting one shot killed make those combat very hard to pass.  I did the same one you describe within your post and probably died like 20 times before passing it.  It took way to long and I mostly just ran, dodge and use Atreus to shoot them and threw my Ax.  

I wholeheartedly agree with the tip of leveling Atreus before Kratos. The way I see it, Atreus is free damage and crowd control and unlike when I purchase an ability for Kratos, there's no chance the AI will forget to use it.

Also, I focused on doing all the sidequests I could before moving on to the main quest and now I feel I might be a bit overpowered since I collected tons of resources, weapons, talismans and armors.

I kept doing favors suggested by Sindri and Brok. Managed to get to Level 5 before beating the game. I was able to take down some of the level 7 foes with "Spoiler" weapon.

The amount of damage Arteus brings is surprisingly much and makes some of the level 7 Revnants an easy target.

I've just completed my first 'realm' shift, and I'm only at level 2....what am I doing wrong?

I';m not bragging, nor am I the type to brag, I just felt like I shoiuld maybe be a higher level than '2' after more than 12 hours into the game

I'm at 3 now, and I just reached 'the summit' which is less than 1/3 of the way through the game