You are overdose when:
Your EQ(erection quality is under your normal level)
When your penis feels very tired
When you can't get 100 % erection
Decrease morning wood
When u have a little pain on your penis.
Then you should:
Rest or take off 2,3,4 days from Pe.
Do a warm-up twice a day
Drink some vitamins.
Stay out of masturbation
And after this days do Kegels(1 day on,1 day off 50 kegel 5 sek.)