Dear Querist
If you are in India and he is in USA then immediately file criminal cases against him if there is any domestic violence or dowry demand or cruelty committed upon you by him.
If you are not able to maintain yourself then you may file a maintenance case against him under section 125 of Cr.P.C. and claim maintenance, 1/3 of His income may be granted to you as maintenance. If he will not appear before the court then the court have power to pass an exparty order in your favour, even you can send him a summon through mail, Whatsapp too.
You can claim protection, right to residence, monetary relief, child custody if any and compensation under section 18,19,20,21&22 of Protection of Women from Domestic violence act 2005.
If he has Indian citizen ship then his passport can also be impounded by passport authority after criminal proceeding if pending before criminal court as per passport act.
But without filing cases against him no law will help you, if you will not file cases against him then he can not be punished for his wrongs.
Cost is depend on the lawyer of your choice.
Feel free to call