seems to me you are over working your chest, personally i would pick 3 of those workouts, and instead of a flat db press i would go with a bb bench press. you can load more weight and its even motion. i like to keep db for incline, dont ask me why it just feels better to me. and then i would just do one set of flies but i do them with db's laying flat. also i would just do this once per week, give them time to repair.
how many sets and reps are you doing?