Too much pressing.
Start on flies to pre exhaust the pecs (4sets).
Then do 2 other movements of your choice (presses / incline flies etc.) for no more than 12 sets. Change the angles each workout slightly, rather than trying to hit all angles in one session - you are overtraining.
Don't worry about lifting the biggest possible weights all the time either, I know you do - hence bench press being your first movement with heavy weight. Do your reps after a warmup at 12,10,8,6. Intesity it what it is about and hitting the muscle fully, if you want to really grow.