Has Online Affair become successful and is it good.. how much can u trust them

I have had a couple of online affairs. A couple of them were well on their way to becoming real world affairs. One of them in particular really had a chance. Unfortunately, things did not work out. Circumstances in my life at the time took me in another direction literally over-night, and I lost all contact with the person for a little while. By the time I could contact her, things had changed. We have both moved on since that time, but I often find myself wishing I had her back. I know that we could have been happy together if things had gone differently. I should have never left. I should have never screwed things up the way I did.