I don't think I completely understand the situation, but I sure hope that someone out there will help you. I know you aren't the only one going through complicated messes like this one, and there will be hope in all this! Best wishes to you, I wish I could help...but my only advice is to not give up, never stoop to their mean level and always keep your son's best interests at heart. You'll see him someday...the hard part of finding him is already behind you! Some spend 30 years trying to do that! There's hardships ahead too, but you can get through them!
Good luck, God bless!