This sucks what should I do ?

Well, I started seeing this girl.She is very nice .She's OK looking and has a nice body .Has a good job, new car .She is always doing things to make me happy . Cooks for me ,takes me where ever I want .We have kick A$$ sex .She says she can see her self marring me.But I can't I'm not in Love or really attracted to her.It sucks because we really get along very well .Always have a good time together.Time fly's when we are together. Should I just keep going with it and see what happens???