But on the other hand, you will probably cause much suffering in this world, you will pay for that with your future suffering; you will suffer for yourself all the suffering you caused. If you kill yourself because you don´t want to pay for that, you are just making things worst, when you kill yourself, you will cause more suffering, and you will have to pay for that and every suffering you caused.
Yes unless your causing suffering is what is necessary to balance karma. Say this man did something awful and deserved--even demanded--to be murdered, then you killing him is not an imbalance in karma, it is instead righting the wrong. Would you still be to blame for being the hand of Karmic justice?
It seems in this sense as though karma itself is a unstable and inexhaustible circle of meaningless retributions and rewards that ultimately cancel each other out and amount to no gain or progress of any kind.