Advice please

This is my fist time posting on here so I apologize if it's done wrong. But I honestly just need help. Me 'M20' and my gf 'F19' have been dating for almost a year now, it has been long distance unfortunately, and she's out of the country at the moment. But when we see each other it does get very "erotic", tho that isn't the issue, the issue is that I struggle with my impulses, and tho I haven't cheated on her financially, I do however find it very hard not to keep looking at other women or flirting with them. I know I wouldn't make the first move, but I don't believe I'd be able to resist if the opportunity arises. I don't know what to do, I want to stay away from other women, but being alone for so long isn't easy. Is there something wrong with me?