Heh! I totally feel you, bro! This is the first year where I've played online fairly consistently. I feel like I am as good as you explained: can't hit squat, other dudes destroy me, I am always feeling like I need to avoid the mercy rule in RS, etc.
While I was enjoying trying to prestige some of my cards' stats while playing online, I quickly realized that I have no real skill online. It's like you said - any time I get a solid hit I feel it's just dumb luck. I'd say more than 50% of my online wins (RS & Events) have come from quits and disconnects. I'd say I've won about 10 RS games fair and square. Same goes for Events. I have no clue how to use the PCI. I've tried it, but can't stay with it long enough to get comfortable and go back to directional.
So what I do now is I go into every online game knowing I will lose - just make it a given. So if I do win, I feel great about it! Even if I'm up I still count on losing. But if I somehow pull off the win, it's very satisfying! When I have won big in rare occasions, I then realize how it feels to play against me! Lolz!
In any case, by having this "loser mentality," I've had tons of fun playing online! Unfortunately, that also means I rarely can prestige my cards that need the prestigin'.
I only have 4 Prestiged cards. Workin' on getting Paxton prestiged but still got a-ways to go.
But hang in there! Losing sucks but have some fun with it and change up your expectations and see if that helps! Good luck, yo!