One last caveat what do you do if despite your best efforts you end up cheating again? If this happens rather than telling your boyfriend you should take a good hard look at your relationship and consider ending it. Youre only human and humans make mistakes and that seems to be exactly what your cheating this time was, a mistake. However, if you do it again be it with the same guy or somebody else it is a sign that you are not as committed to your boyfriend as you should be and the only right thing to do is end the relationship. Sometimes cheating is nothing more than a stupid mistake born in a moment of weakness, but other times it is a sign that something is not working in the relationship. If you find yourself cheating again it probably means you are not happy in the relationship and subconsciously want out. In your case it may be something as small as his being far away at school that is causing you to feel dissatisfied, you may genuinely love your boyfriend and it could be that loneliness is behind your betrayals, but regardless no relationship can grow in the shadow of infidelity. So should it happen again I would urge you to break things off. But again, in the interest of what is right, keep the cheating to yourself when you end the relationship. There is no need to rub salt in the wounds of your boyfriend even if it does clear your conscience.
Good luck! I hope that you dont cheat again and that you and your guy make it through this unscathed. Some final words of wisdom; forgive yourself and let go of your guilt, be a better girlfriend in the future, only tell the truth if your boyfriend brings up the subject and finally, if it happens again end the relationship with as little drama as possible. Cheating doesnt always have to end a relationship but in the end the only person who needs to deal with the pain of what you have chosen to do is you. Confession may be good for the soul but it isnt always the right thing to do!

