kudo's on not offing yourself after that day. I fear many a 19 year old, especially in fluffville, would have after the events of that day.
yikes...
I believe that there absolutely can be emotional cheating, but I also feel that cheating emotionally may not be grounds for a immediate breakup.
It is easy to find someone who, at our particular point in life, feeds us better emotionally than our significant other. You may laugh with them, cry with them, bitch with them, etc, but you still go home to your spouse. But that can very easliy lead to physical cheating, so ya gots to be careful.