If you buy this Kindle book for $1 it sums up what a healthy, happy relationship is.
[url=http://www.amazon.com/Dating-and-Relationship-Basics-ebook/dp/B005H3ZRE4/]Amazon.com: Dating and Relationship Basics eBook: Chuck Roberts: Kindle Store[/url]
Other than that, we are not mind readers. We cannot know what went wrong with a relationship, or why the next relationship was better (or worse).
I have a long time interest in psychology, specializing in relationship dynamics for 30 years.
(Please note, we give the best advice we can based on the information given in a post. For better advice, please include the age of all romantic partners.)