Friends i need your help. Pls say whatever you can. Seriously in need of advices?

I am a bachelor,27,working with a MNC,in love with a single mother,34, who is in the process of getting divorced. my mom(an officer) knows everything about it.(I lost my father long back and have a younger sis). The girl's hubby was cruel no brutal i must comment. On one side lies my mom who worked too hard after my father to bring us up did all the hard work required. on another side is the girl I love and i want to bring a peace of happiness to the max I can. As she too had gone through a terrible time. Lost 10 yrs to manage the marriage but all in vague. it has been more than 1.5 yrs to this relationship. My mom is quite possessive and even not ready to allow me to go out of town, on a job. A male can't survive like dat. She is spying each and every movement of mine, treating me as a homely girl (that's usual) and seriously use the words for her , she should not. i am planning to leave my home in few days but I have responsibilities for both of them. I can't leave anyone of them but yes if i stay at my home i won't be able to grow up ,to take my life's decision on my own,and will be a momma's boy for whole of my life, i will have to ask/follow her and this possessiveness is harmful for my mom too. i want to take decisions on my own, spend my life with her ,strike a balance, performing my duties for mom at the same time. I want to earn and secure my mom and sis and give what my girl and the little boy who is in boarding right now, deserve. Is is sinful? if i bring a small smile on the girl's face or her destiny is to die/live poorly due to a bad decision in her life??don't we take bad decisions , at least once in our life? WHAT SHOULD I DO?? I am seriously confused. i love both of them very much . they both need me. The only differnce is that my mom has my sis (whom she loves more) along with her and the girl is all alone without any home.My sis is in the town for next 6 months as she is working with an MNC too. Kindly write whatever you feel like . But please don't banter. Its quite serious