Divorce for adultary and child custody

I am 40 years old man, married for 12 years now and have a son of 11 years, 5 years ago I caught my wife using another phone at nights, when checked there were dirty mesages exchanged, she accepted adultary, she wrote a letter to me since we wer not talking for few days stating what she was doing was wrong and will not continue, i also got to know she had affair with this guy before marriage and also had an abortion, i still decided to move on forgiving her whole heartedly, couple of years later again i found some signs and tried to find out and found she was sleeping with him and gave some weird resons some money is stuck with him from past ,i asked to stop all this and moved on, again i tried to move on keeping in mind kids future.. since then i am having a watch on her.. she was even using her frnds to talk to him going to their house, never accepted, again warned her, she created a different social account, she denied it was hers, i have recorded a few conversations wher she is sounds like still in touch with him and his frnds.. i have requested her enough that we will move on and let go past she says she does but still continues to talk behind my back ... Her frnds and even her mom is aware and may not testify. i have tried enough to save this relationship and failed, mentally gone through a lot of trauma, stress and even been on anxiety medicines, i have never physically abused her.. she says i should stop monitoring her, when i stop after few days again i find something and get hurt Proof : I have hand written letter given by her, mobile i found out, messages in it chatting dirty things, some recording which proves she is still in touch, in one recording she says if I don't get child custody she will give supari to kill me, i have always thought it is due to her short tempered nature, but not sure Even now if she willing to leave everything behind, find happines within family, i am willing to accept and move on for the sake of families. I want to know how court will treat this care, if applied for divorse 1. Will I get child custody, I am worried for him 2. If child custody is not given will i have to pay maintainence for no mistake of mine 3. I have build a house in their property and still in loan and i invested all my saving there. How will this be treated. Kindly advise