Pursue new hobbies and renew old passions. Join new clubs and sports or recommit to old ones. Take the time and energy you previously spent lusting after your teacher and put it towards something productive. Also try to get out and find some new people to spend time with to get your mind off them. Develop relationships with other people, especially people your own age. Work on strengthening current friendships and cultivating new ones. Open your mind to meeting and spending time with new people and you may find yourself falling out of love faster than you think! Taking a trip or changing up your surroundings is incredibly healthy. Traveling can help you expand your mind and see the world in an entirely new light. Traveling also teaches patience, flexibility and perspective; which are all important qualities that will help you get over your teacher. The best way to get over an old relationship is to get involved in a new one. Don't rush into anything you're not comfortable with, but allow yourself to be open to the idea of dating and pursuing relationships with new people, because you have to move on. There's no agreed upon length of time to wait after suffering a broken heart. But it is important to take some time to yourself after a breakup to rediscover who you are, what you like and what you value in yourself and in a future partner.
Distract yourself with extra-curricular activities. Spend time with friends. Go somewhere new. Date someone new.