So, that's a relationship, then.
* You will feel sadness and regret and nostalgia, no matter how bad it got. That's normal. It's also NOT a sign that you are on the wrong path.
* If all parties involved can actually decide to be civil and friendly, that's far easier and healthier. But if one person doesn't want to do it that way, then it's out of the question for the time being.
* You can learn a lot about yourself and relationships by fucking it up. So yeah, having more marriages (or relationships) does not necessarily mean that you're bad at relationships now... And you're quite possibly better than when you started.
Anyway, I wish her well. While it didn't end the way either of us expected, that doesn't mean she, I, or the relationship was bad.
And that's an important distinction to make.
And now, onward.