I see this type of post or comment a lot throughout the thread. A lot of this comes down to being able to effectively "manage" a defense, aka reading the offense and calling plays accordingly.
On defense I play "coach mode" in order to keep a sim feel to the game because I felt the Jags D was
too effective when I played as an MLB or DE. So, I call the plays (from the Strategy screen) and make any audibles or line shifts and that's it. I sit back and watch defense from Broadcast view.
If the CPU QB is picking you apart then you are not getting pressure on him. Any NFL QB with enough time will pick apart a defense--that's why they're in the league.
If your front line can't get pressure against the O-line then you need to have at least one blitzer every time you are playing the pass.
If your DB/WR matchup is failing you on man-to-man coverage, you need to make the switch to zone and plan around containment (and get pressure on the QB).
These sliders and Armor's guidelines for CFM give a phenomenal experience in Madden 16. The game plays great and requires good play calling on defense.