Being you in a relationship is emotionally fulfilling
Too often people will get in a relationship that doesn't work, and when it ends they mope and whine and then say, "They didn't like me because." Sometimes the dot, dot, dot becomes something they worry about, or think about changing. They think that if they develop that characteristic, or change that problem, etc. that someone else may like them more. There are times when this is a positive thing. For example, of those dots are "I smoke" and they decide to quit, then that is a good thing. But what if it is, "I like Star Wars"? Should a person have to change who they are, or pretend to be something they aren't to get love? No. The fact is if you are in a relationship as yourself, it is far more emotionally fulfilling.
When betrayal occurs in a relationship, it can literally ruin the years it has taken you to build trust and to have a healthy relationship. If something has occurred that has caused the trust to be shaken in the relationship, what can you do work on regaining trust in the relationship? The frustrating part is that it does take years to rebuild trust in a relationship and its not going to be easy either. If you are the partner that broke the trust, you will need to find a way to convince your partner that you are trustworthy again and that you deserve to have a second chance. If you are the partner that was hurt, you will need to learn how to truly forgive them and to determine if you really want to offer them a second chance or not.