It sounds like your confused by what you think you should do and what your heart really tells you to do. There's a huge difference but sometimes you can't see it until it's too late.

When I was 18 I met a girl who's best friend was dating one of my best friends. We hung out a lot and eventually ended up together. Her family was moving out of town, she didn't really want to go, and we ended up getting an apartment. After a year or so it just seemed like we should get married, everyone kept asking when, etc, etc. So we got married. Within 2-3 years we were living more like roomates than a couple. Granted, we were both working and going to school full time so that meant little time for anything else. But even when we'd both have free time, at the same time, we usually ended up doing seperate things. About 3.5 years after we were married she moved out, a year later we were divorced.

A year or so after my divorce I met an incredible woman who I instantly had an incredible attraction to. It was literally love at first site. Apparently she felt the same and from the first date we were inseperable. Withing a month of first meeting her I knew without a doubt that she was the one I wanted to spend the rest of my life with and proposed. It wasn't because we thought that was what we should do, or because anyone else thought we were "such a good couple" it was because we absolutely knew in our hearts that we were meant for each other. We now have a beautiful 3yo little girl and tomorrow, yes literally tomorrow, we celebrate our 10th anniversary.

My advice is this, if you are having doubts, she's not for you. Before you marry someone you should have that incredible feeling in your heart that tells she she is the one. If you don't have that feeling, she isn't.