It depends where you are if it is illegal or not. Ages of consent here in Australia range from fifteen to seventeen. I would say it is not illegal where you are.

Wrong? That depends. A relationship between any two ages can be wrong. I've been in relationships with people my own age in which I've been cheated on and abused. That was wrong. I'm currently in a relationship where the age gap is similar to your own, yet it's been going on for over a year now and I wouldn't consider it wrong in the slightest. But I have no idea what's going on in your relationship, so I can't really be the judge of whether it's 'wrong' or not. That's your desicion.