Personally I think you should please yourself. As time goes by this becomes more and more difficult as other resposibilities take over. Yes, you like your school but there are other good schools out there. You have proved your worth so should get a good reference. Ask for a reference if you do resign. You don't have ties at the moment. Who knows how long this will last? Go while you can. Follow your dream. At least you will never regret it. But you may regret not doing it for the rest of your life. It will be a great experience, it will change you in some way. You will grow as a person and have more to offer. Do it. I wish I had but I was too scared. Good luck.