out of sight, out of mind is what i always say about long distance relationships. perhaps, you two can continue to be friends. give up and don't bring up a romantic relationship topics at all in order for that to be successful. maybe, in time you can strike up romance at some other point in each other's lives or you both may find that having each other even just in friendship will prove to be helpful and fulfilling from now on
Well they fall apart for several different reasons, hell too many to even list. That is why most people do not marry the first person they date.
Not to sound cold, but it sounds like it's time to move on.