Can they do this with child ?

i filed for support and when the day came to show our checks i showed mine and he didnt show his...he nly said he has 32 hrs... the person didnt bother to check his stub.. so i told the judge that i dont believe that he is only working that much hours... so another court date was set...the next court date he showed his paper work and now he has more hours im getting less support because they are including his visitations with our child... which is a day... is that possible can they do that... the whole point in me asking the court to review his pay stubs was because the first amount wasnt enough... now its going to be less... and i know he gets a lot of money and that he is just lying about everything... he just doesnt want to give us support... what can i do abut this... its outrageous... he didnt give support since our childs birth and in our state, its only retroactive from the date the person files... but the reason i never filed was because he told me not to and tht he would give us monthly support and that he would help with our son... when that never happened... i filed... he never went to visit his son and he was telling the courts i was refusing him to see our son and thats why he is given visitation... but now he has visitation he is paying less support... our son basically is only over his house for a day... i mean im really getting screwed here what should i do?