What i'm starting to realize is that you can only put so much into a relationship... In order to avoid feeling that pain and sorrow, you have to really stay your own individual and maintain your sense of self. Once you reach the point where the person you are dating is in control of whether you are happy or not, you've lost the battle and are setting yourself up for disaster. I lost my sense of self about 15 months ago, and i'm really on a painful journey of self discovery right now.
Be careful with your heart, because when someone seems too good to be true, they usually are.