I was someone's rebound, didn't realize it until the second time around. Somehow I'm the ******* in that one. Just lowered my faith in others honesty. It's why I don't like Bianca and sort of identify with Varric. He's a wuss, and I was too in that regard.
I don't think any of us are wusses for falling into relationships. We we're all mortal, and we make mistakes. Try not to let someone lower your faith in others, if you can. You made an error in judgment and learned from it. <big hugs>
For the record, I felt the same way. I was more in Varric's shoes with my first fiancee. Wasted 4 years of my life on that twit. 
Edit: Something else I thought of. None of the relationships between the PC and the LI have really ended on a great note, especially for the other party. DA:O? Well, you leave regardless, die or even if you ride off with Alistair as a Warden, the Warden hero is MIA and Warden Alistair comes back to be possibly left in the Fade. They are obviously far apart, no matter what.
With Leliana, she's MIA from the Warden, same as Zevran. With Morrigan, he had to leave behind his love and his child.
Regardless of whether or not Hawke is left behind, s/he's separated from the person they love to protect them. In the case of the Anders romance, it's to protect him from Cory's influence. Even if s/he isn't left behind in the Fade, they've disappeared for now.
Yeah, maybe Varric was the one that got lucky here.