Effect of past life

Q. I too believe that GOD exists. But very recently I have been experiencing very bad moments, whatever I think it doesn’t happen, whatever I touch it gets postponed, wherever my name is involved the work some how mysteriously gets cancelled. So I started checking my numerology and astrology online, people tell me that our present life karma is based on past life deeds. Is it true?. Is our fate is already written by Brahma, are we just puppets in God’s hands. I checked my last life jyotisha in some astrology website it says that in my past life I was a big cheater and also based on my name numerology I carry my past life karmic debts to this life.
I don’t understand why should I be responsible for my past life which I have no clue about, why can’t God punish people in the same life itself for their misdeeds and give everyone a fresh new life. My main question is can’t we change our fate written by Brahma.

A. One’s karma is based on one’s deeds, not only of one past life, but of many many past lives.
Everything is calculated very precisely. 

The nature of this material world is such that there are always some reversals and challenges to face.

It depends upon us as to how to take it, positively or negatively.

Everyone has a baggage of good and bad deeds. And we have to nullify it, positive for the positive and negative for the negative.

If something good happens, one must know that one is exhausting one’s good deeds. Similarly, when bad things are happening, we must know that bad deeds are getting nullified. So one has to suffer less in the future.

If one remains steady in both happiness and distress, then one can transcend the dualities of this material world.

We cannot change the circumstances, but we can certainly change the way we perceive it.

Real positivity means to turn any difficult situation into an opportunity.

We may not remember our previous bad deeds and the sufficient punishment is not given in the previous life.
Because we may not have sufficient karma to suffer.
Therefore, karma is very inconceivable and difficult to understand.

The message of Bhagavad Gita explains how to not get affected by the karma.
It is possible to change the karma and the destiny.