Try not to be too clingy to your partner or over obsess about what they are doing at every minute of the day. You also must set some ground rules between the both of you so that nothing unsavoury can happen. For example, you can tell your partner that if he meets another partner and becomes interested in them, then your partner must tell you and break up with you first before proceeding with the other. Such rules can help establish a buffer which prevents getting hurt.
Frequent communication is extremely important for long distance relationships, and is totally possible especially since the advent of instant messaging and emails. Communication helps each partner get updates on each other's lives, which is crucial for the progress of a relationship. Overcome the long-distance hurdle by making time to chat with your partner everyday.
Long distance relationships can work if you are determined and committed enough. Keep regular contact but not to the point of being a pest. Be sure that both of you have agreed with what is acceptable and what is not - such as going out in groups or singly with others. You can use Skype to still do things together, like play a game or watch a movie. Make visits very special and don't waste them fighting over insignificant things.
Long distance relationships are sustainable. View it as a learning journey for the both of you. A pithy Chinese saying goes, “Real gold is not afraid of the test of fire.” Instead of thinking that a long distance relationship is pulling you two apart, you should believe that through this experience, the both of you will be bound together even stronger. In order to sustain the relationship, set consistent meet-ups, do not overdo communication, and practice good listening.
Long distance relationships are based on trust. So that's one thing you'll definitely need. You'll also need lots of communication or the distance can draw you away from each other. Lastly, you'll need patience. Patience to make it work and understand your partner's needs from so many miles away.