A lot of times, when a relationship is broken, it suddenly looks
much better than it really is.
I've known people who've taken years to sulk over a broken
relationship. Deep inside, they're not just nursing their hurts,
they're also secretly nursing hopes that what they had will one day
be reinstated and restored. BUT, they forget about all the bad
things, choosing only to idealise the good times.
It's time to let go and move on. It's been three years already.
There are so many people out there to know and one of them might
actually reciprocate your affection.
Besides, what if she does return to you? Do you think the
relationship would be problem-free?