If you have been training incorrectly for so long go back to
basics.
Train full body 3 x week. Focus on the movement patterns mentioned
above.
Do this for at least 4 weeks.
Each workout vary tempo, reps (eg. day 1 - Tempo 2-0-1-0 Reps 9,
day 2 - 5-1-1-0 Reps 6, 1-0-x-1 Reps 3) - this is just an
example.
Keep training time (from first WORKING set to last set) under 40
min.
Don't read bodybuilding mags - and stop listening to your
friend.