Why they take away or give me too much points?


That is because the ratings of new players are very uncertain. That makes sense because you haven't played many games and all we have is your word for what kind of a player you are.
Ratings adjustments are large for new players in order to help reduce the uncertainty about your rating. Usually, after a dozen games or so, the uncertainty is greatly reduced and the adjustments get much smaller.

That is because the ratings of new players are very uncertain. That makes sense because you haven't played many games and all we have is your word for what kind of a player you are.
Ratings adjustments are large for new players in order to help reduce the uncertainty about your rating. Usually, after a dozen games or so, the uncertainty is greatly reduced and the adjustments get much smaller.
I understand, but I am sure weaker players would find their ratings dropping rapidly even with the standard addition and substraction.
Now I have played 14 games, and still looking forward for things to settle.