advice po about marital relationship

hiwalay po sa first wife kasama ko and pinakasalan nya po me at nkaregister po sa NSO marriage nmin pero lumalabas na 2nd marriage na nya ang sa akin.magkano po ba payment sa abogado pa erase name ko sa nso?coz null and void kasal namin since the start?
my 2nd problem is i need a lawyer soon for my case to whom can u refer me to speed up my legal filing?
3rd is ngbunga pgsasama nmin ng 2 bata at ngkkalabuan ang aming relasyon due to his other woman affair.gusto ko patanggal surname nya sa mga anak ko and use my family name. my son age 5years and my daughter is 2years.
4th. gusto ng kasama ko hatiin namin anak ko but di me pumapayag what ground can i file to him if ngmamatigas cya give 2 year daughter ko?if itatago nya sa akin ito?

your proper recourse is to file a petition for declaration of nullity based on bigamy. your children will be deemed illegitimate and will carry your surname. you will have sole parental authority over them.

cost depends on the lawyer that you retain. 50k would not be unreasonable.