Guys and Girls, please help me out here.?

Guys and girls I am in a relationship with my long time best friend. Our parents are aware of our relationship and has given their blessing. We live together and I love her very very much. She is my one true love and i know shes the one for me. MY problem is that fortunately or unfortunately I am very sexual person and my gf is the direct opposite. U could say that I am on one end of the sexual spectrom and my gf on the opposite end. For a long time I din care about this and tried to only think of the love we have. I consoled my self that mental gratification is better and more impotent than the physical one. But in time i started feeling depressed and sad about this lack of physical contact bitween us and it has started making me irritated and grumpy all the time. I even lashed out at her a few times and i fear we are slowly drifting apart. I tried to talk to her but still no response. I love her too much and don't want to loose her. I have decided to have sexual relation with other women so that i can save my relationship and this decision has me stressed out. Am i doing the right thing?? Is it wrong of me to satisfy my urges? Or should i continue living my life suppressing them??