Does anyone ever think about innocent partners and children?

To my dismay my partner was unfaithful to me, when he had a one night
stand with a fellow acquaintance. To make matters worse an innocent
child was born, where the father (my partner) does not participate in
the child's life, and the mother has been on the dole for most of her
life. Even though my partner wasn't aware of the child, until the
woman was in her third trimester; I understand and agree that he has
some form of financial responsibility to the wellbeing of the child;
after all, there obviously was no form of protection used. What I do
not agree with though, is the lack of support, compassion,
understanding and fairness given to the father's existing partner and
children, who were there before this disdainful scenario transpired.
Does the child support legislation support the trauma that the
existing children &/or partner may suffer? Does the child support
legislation fairly distribute the father's funds to this new child in
addition to the needs of his existing and future children? On both
accounts I say NO. At no time throughout this ordeal did I receive
any support. I couldn't give a toss about receiving financial
support. I don't need it! But there are no organisations out there
that actively advertise the fact that they provide partners and/or
children, support for dealing with and/or reconciling/repairing their
family, after such a setback. Coming back to the child support... I
loath the fact that this child receives more money than my partner is
able to provide to our children. Why the bleep bleep bleep does this
child (and it's mother) require more funds than me and our 3
children?!?!?!?!?! In the end I'm busting my ass off raising our
kids, paying the lionshare of the bills, while my partner contributes
to funding his illegitimate child and it's mother, who can easily fall
pregnant, but can't seem to stand on her own two feet financially.
Ok, enough is enough. Now I'm rambling and need to stop. Is there
anyone else out there who is in the same boat as me????