Low sexual interest in women. One.

Me and my wife had been married for 2 years now. We have a good rapport and relationship. She loves me lot than anyone else in the world. She is a very good wife and i am happy to have her in my life, she takes care of everything at home. But she has very little sexual interest, everytime i need to convince her to have intercourse. She rarely makes a move to have intercourse with me. We got to know that she has a small ovarian chocolate cyst when consulted a gyno. She says she feels averagely just twice or thrice in a month to have intercourse. I get frustrated and masturbate by watching porn videos, now this has become a routine and i don't want to do this. I don't want to hurt her but i am not sexually satisfied. Could anyone please help to find out if this is because of an physical issue or emotional one.