Marrying a married as second wife whose wife is alive

Hi. Am latha from tamilnadu. I am a physically challenged girl who is affected by skeletal joint disorder from birth. It restricted my mobility so am always staying in home.I cant walk properly but can move a little with help of crutches and can do my works am 34 years old and not married yet. So many men came and rejected me for marriage through marriage bureaus and matrimonial sites. Even Physically disabled guys also rejected me for the reason that am not fit for doing all house hold works. Being in such a lonely frustrated state of my life, Recently i met a man .He was a pharmaceutical manger. We met many times i hospitals when i go for my regular physical check ups.i have a relationship with him who is married already and having 3 kids. Unfortunately even after knowing his marital status we fall in love and united physically also. Am the only daughter to my parents. I have no siblings. After my parents lives i have no one to take care of me. so i tied up in this relationship. But he is living with his wife and family. I never disturbed them in any way. In fact am morally and financially helping a lot for his family. Am an english literature scholar and taking tutions and data entry works from my home. Whatever i earn , i am spending for them only. His wife is well known of our relationship.At first she disagreed but now she realised my true nature and my offerings of helps to his family. What is my problem is, She is getting all benefits from me, but not even allowing me to talk to him even in phone. Now a days am worrying a lot about this family's selfish and deceiving nature and what will be my future status after my parents. Am not a cunning girl to separate him from that family. I just want his love care and a moral support after my parents. But i heard that there is no favorable rules in indian laws for the second wife like me. He says just have a baby through him, so that even if his wife doesn't allows him to protect me, my child will be there for my future.Am whole heartedly loving him a lot even he comes once in a while and dont want to settle with any other man That is his suggestion. Am totally hectic.. kindly guide me if any law professionals read this.