Child support question?

Hi i just received court papers and i have to go to court for a review on maybe having my child support raised again.I pay 450 dollars a month and i have never been behind and my daughter is almost 16 years old.I have not seen my daughter since she has been 5 a very long story on that but that is for a different time.I have a 3 little boys 2,5 and 7.The 2 year old is mine but i have 2 stepsons that are not but i love them like mine own.Their father has never paid any child support on them and doesn't want them period.I have been their father and paid for clothes on their back food on the table schooling and etc.I recently told child support people i had two stepsons and they basically said so that is not a deduction because they are not mine which i found ridiculous.So they just gave me a deduction for my 2 year old and was a low amount.My daughter dollar figure was alot more than my sons.Anyway i'm thinking about getting a lawyer and fighting this and just seeing if i can keep the payments the same or even lowering a little bit.What do think my chances are on having this done?