You are not alone. I feel like the worst gamer in history. Here's my situation. Just restarted the game and finished the tutorial. I jump off the forge tower and sneak around to scope things out but never move farther than 30 feet. I get spotted and a scramble back up to the tower until everything quiets down again. I jump back off and am hiding 400 feet away from a Orc targeted. I'm in a bush in stealth. Some nasty dude named Unstoppable appears from behind and whoops on me until I scramble back up to the tower. All of this and I haven't killed a single Orc since the tutorial. What the hell? I love this game and will keep playing but I'm just not good at all.
Protip: if the game is too hard, focus on yellow story missions. You can easily run past everything, so just sprint/parkour your way to each of the forge towers until they're activated for fast travel; maybe hunt for collectables to give you easy points for levelling up your health, and focus on story missions which will unlock core abilities.
The game's balance is very weird. You're pretty underpowered to start with, but as you play you become so godlike that many people find the game too easy. Saints Row 3 and 4 suffered from this too, and Shadow is significantly better, but there ought to be a NG+ or a Death Threat+ that massively levels up the orcs.
That said, I'm still having a blast after 30+ hours. Just got a rune that ignites 15% of my throwing daggers. Feels closer to 33%. Never bothered with them before; now I use them all the time. Same will be true of Shadow Strike when I grab Shadow Strike chain.
For me, the combat is more than varied enough to hold ny interest, and I still die now and again because I'm not slick enough to breeze through combat with prompts turned off and no health upgrades. But I shouldn't have to gimp myself.
The sequel will benefit from better balanced difficulty (Death Threat is an excellent start) and more varied sub-missions that present players with different ways to play. Nevertheless, for a game as ambitious as this one, this first entry gets an enormous number of things right.
Haven't bought the season pass yet, but I will. Best new gen game I've played, just edging past Wolfenstein. The latter is the better game, but I'm having far more fun with Shadow of Mordor than I've had with all the new gen games I've played put together.