What to do not getting any way

My married life lasted for 13.5 yrs. One son of 12.5 yrs. After married life of 8 yrs my wife got engaged with a boy and started luving her and on my oposing started qurrel at home n threatened me to file a complaint of harassment and domestic violence if I opesed her frndship. Her relationship lasted for 4 yrs and after many objections and qurrrels that boy left her, but she blamed me that he left her because of me so she will not lete live happily. She doesn't behave properly at home doesn't fulfill her daily responsibilities doesn't take care of my son goes out of home without informing she even started drinking and smoking, and when I started stopping her she started qurrel and now started going to my boss complaining that I'm not behaving properly at home. She used to run away from home without informing n then calls me and says that I'm leaving city going to any unknown place forever and cathches any train or bus and after informing me switches off her pH so that I should be tensioned and should run behind her for her search, many times I did this but all in waste. Slowly I got to know that she is doing all this only to make mentally harass. Many times she goes out of home without informing and when I call her to ask abt her whereabts she says I'm not going to come back and I'm drinking and roaming on roads so that some wrong incidence should happens with me and then she switches off her pH and she usually comes back home late after 01 in night. In this regard I have given a complaint in the month of September last year informing police station that she is doing this type of activities and I should not be blamed of any mishappening with her. After that she started drinking and smoking heavily. Some boys of my building have seen her drinking many times even on Christmas two boys among them brought her totally in drunken state when she was in auto and was not able to trace the way to her home. Last month also she ran away and came after three days and again took her clothes and went to her parents home and after three days came back kept her clothes took one of the key of home and went back to her parents home. Her activities are creating and big mental pressure on me and on my grown up son. She usually calls me asking abt my whereabts and saying what rvu doing there. Why are u there and all and starts qurrel and starts abusing me so that I should go under pressure.I have asked many times to her that it's not possible to live together so why don't we should get separated. She says I m not going to leave you nor I'm going to give u anything in written, then I said OK dnt gv anything in written but live separate . in this case also she doesn't let me live happily with my son she always calls againg and again and disturbs me and if we doesn't pick her call she comes home to fight. Evry now and then She threatens me that she will file false complaints against me for dowry and domestic violence. She always say I m going to gv u divorce in any case. She uses very volgure and abusive language for me on calls and even abuses to my friends who ever supports me in n any type of help me as a friend so that I should live alone and get helpless to plea in front of her. Plz suggest me what should I do. I want divorce and my son wants to live only with me.