I have a good defense as well and in the beginning, teams were able to throw on me at will until I decided to change my strategy. I do blitz a lot but every now and then, I go zone or man coverage .. my trick is, after calling a play, click X while your line is setting up and choose
adjustment and then choose
show blitz.. now when you actually blitz, their offensive line won't know who to cover since they are all in the line of scrimmage so someone is bound to get open to sack their QB, now if you choose zone, deep or man coverage, their QB will end up passing too quick (since he would think that you are actually blitzing) leaving the ball ahead or behind their receiver (usually behind) ... just mix it up with blitzes (different kinds) and cover and you will sure mess up their passing game