did she know that you intended on marrying her?
Just be upfront and honest about your feelings.
Everyone always says communication is key in a relationship, and that's definitely true.
So communicate.
Sometimes it's right to just move on and learn from the experience.
Some people invest years into a relationship, and it could very well be the wrong relationship, but because of the years invested, some people feel like they need to hang on and keep it going.
Finding out whether it was really meant to be or not is the difficult part.
I don't envy that situation, that's for sure.
Been there, done that, glad I learned and moved on.
Good luck to ya.