Is it normal that you want someone but not really?

24-1-16
So here's a part of the story that should be meaningful for the question.

Let's start at the beginning. I met this girl from a dating site and she and I became intimate. She didn't want a real relationship with me though. Turns out - it was because she has been in a relationship. My world was destroyed. On the other hand I was thinking everything I wanted came back to me because I only wanted to do it with a girl and I didn't care who it was. Maybe it became more but that doesn't change the fact of how this thing started in the first place. Anyway I knew in my heart that she wasn't the one. Starting from the fact that for her appearance is more important than brains. And I should've known after she laughed at my life goal. All those little things didn't stop me though. It is a shame that I didn't take better care of myself.

Anyway, the s** was so fking great though and I have trouble letting her go. Feels more like I hate to let an investment go. To let go of "my property". It's not love but I wanna be the one to protect her and to make her happy. I feel like my Ego is more hurt than the fact that I might've liked her more than I did. Is it normal to not being able to let go of everything? Even if it isn't love? And even after knowing she is a burden to you, that you just want her in your life because she's fun and gives you distraction?