Hello, if i have a movie promo mewtwo as my active and have 20 damage on it and i did energy absorbtion for two potion energies, do i still take 20 damage away from mewtwo. Thanks

No.  If you read Potion Energy closely, you will see the card states, "When it comes into play from your hand."  Potion Energies that get Absorbed up are coming from your discard pile and not your hand.