Friends:

Effect of action is not fixed, but modifiable by new action:

Painful effects of wrong action is reduced by new right action.
Painful effects of wrong action is enhanced by more wrong action.
Pleasurable effects of right action is reduced by new wrong action.
Pleasurable effects of right action is enhanced by more right action.

For details on the mechanics of Kamma = Intentional Action see:
http://What-Buddha-Said.net/drops/II/Kamma_is_intention.htm
http://What-Buddha-Said.net/drops/II/Buddha_on_Kamma.htm
http://What-Buddha-Said.net/drops/III/Kamma_and_Fruit.htm
http://What-Buddha-Said.net/drops/III/Inevitable_Consequences.htm
http://What-Buddha-Said.net/drops/II/Good_Action_dilutes_Evil_Kamma.htm
http://What-Buddha-Said.net/drops/II/Kamma_leading_to_short_&_long_life.htm
http://What-Buddha-Said.net/drops/II/Kamma_leading_to_Health_&_Sickness.htm
http://What-Buddha-Said.net/drops/II/Kamma_leading_to_Low_or_High_Birth.htm
http://What-Buddha-Said.net/drops/II/Kamma_leading_to_Wealth_or_Poverty.htm
http://What-Buddha-Said.net/drops/II/Kamma_leading_to_Beauty_&_Ugliness.htm
http://What-Buddha-Said.net/drops/II/Effect_of_Action_(kamma)_is_Delayed.htm
http://What-Buddha-Said.net/drops/II/Kamma_leading_to_Power_or_Disrespect.htm
http://What-Buddha-Said.net/drops/II/Evil_Kamma_enhances_other_Evil_Kamma.htm
http://What-Buddha-Said.net/drops/II/Good_Action_enhances_other_Good_Kamma.htm
http://What-Buddha-Said.net/drops/II/Kamma_leading_to_Stupidity_or_Intelligence.htm

and:

AN 3.99 Lonaphala Sutta The Salt Crystal:
http://www.accesstoinsight.org/tipitaka/an/an03/an03.099.than.html

Kamma & the Ending of Kamma:
http://www.accesstoinsight.org/lib/authors/thanissaro/wings/part1.html#part1-b

Kammic effects can be modified!
Kamma is improvable!
Never give up!