This is no coincidence. These are the most difficult hands to play. Very strong hands and very weak hands tend to outperform their equity (strong hands because they can value bet, weak hands because they don’t have much equity to begin with so any time you do manage to win the pot with a bluff or whatever it’s a nice little coup), while marginal hands underperform theirs. It’s as you say: no matter what you do, it feels like you’re making a mistake. When you bet, you often run into better or get check-raised or whatever. When you check, you often get drawn out on or bluffed out.

In terms of resources from me, have you read Play Optimal Poker? I’m working on a sequel now that should do more to answer your question, but I think the original will still be helpful. Or any of my HH reviews on here, you’ll see how I handle these decisions in real game situations. But it is about striking the balance. The less vulnerable your hand, the more inclined you should be to check. The more vulnerable, the more interested you are in betting. Don’t forget that betting small is an option, not every bet has to be 50%+ of the pot.

Hope that helps!