Hello,
1) If there is a protection order on place, move a petition before the court about continued violence and atrocities and seek intervention.
2) If there is no such order approach the court immediately seeking protection and prohibitory order against your husband seeking appointment of a protection officer.
3) Though your husband has bought the flat in your name as long as it is registered on your name he can not lay any claim on it as you are the absolute owner of the property. You can complain to the police regarding trespass if he breaks into the house using force.
4) As the DV case is still pending, move an interim application seeking prohibitory order seeking immediate intervention by a court order under provisions of protection of women against domestic violence act. Any act of your husband contrary to the order will land your husband in jail.
5) You can file a case of adultery against your husband regarding his illicit relations with the much married woman. This will initiate proceedings against your husband. To get any action against the woman get help of NGOS of the area who will involve and put her in spot.
6) You can also ask for maintenance for your minor son, yourself and expenses for the daughter's wedding etc . This forms part of your husband's liabilities though he has taken steps destroying the marriage.