1. This is trypical amtrimonil proboem and not a legal one.
2. Such dispute is first tried to be solved amoicably.
3.if that does not happen then you have to think whether you want to live life with her in this way or come out of this.
4. if you want to come out then ask for mutual divorce.
5.If not then file contested divorce suit.
6.Since there is child I would ask you to talk to her and give some time so she changes and things normalise once again.
7.If dispute does to court and your wife keeps the child then you will get chance to meet him but getting back the child is almost impossible.