affair

Iam a 26 years old man living in a remote area of India and work as a govt. officer. Iam living alone ,so i hired a lady cook cook for me. I paid her for that. She is 48 years old women and a childless widow. But I dont know what happen to me, i attracted towards her and proposed my love to her,She accepted it and later we started physical relation.It was since february, 2015 we shared bed regularly sometime twice in a day. She is illiterate but now she plays like my guardian and dictate me in day to day life. But i dont want to marry her but she insisted for formal marriage. Icannot leave her too. Now what can I do. She give me sex which is very pleasurable with her and i cannot leave it now. Now what can I do? Please advice me .