You have many options.
1. File a complaint under protection of women from domestic violence ACT 2005, under sections . 17 to 22 , for reliefs of residence order,prohibitory orders against the husband,compensation , maintenance, custody and for return of your articles, etc.
2. You should lodge an FIR if the husband' girl friend is married .Adultery is applicable under 497 IPC only if the lady in question is married. But this will be a ground for divorce in divorce proceedings on basis of adultery .
In case you want a divorce file a divorce under grounds of adultery& cruelty , ask for return of shtreedhan and articles, and also ask for alimony , a Residence and maintenance for your child.if you are planning to file divorce it is better to ask all these reliefs along with the divorce petition.
Since the FIIR under 498A is in effect, he might settle this with you.At that stage you can ask for your one time alimony and go ahead with a mutual consent divorce.