Long term relationship - waste of time?

Hi, I've been in a relationship with my girlfriend now for 2 years, and we have decided to move in with each other. I love her, she's my best friend, love spending time with her etc, however, I'm still not sure if she's the girl I want to marry. My question is, is this relationship a waste of time? In 2 years, if I'm still not sure, is that a sign that she's not the one for me? As we've been together, my friendships have suffered, and I rarely see my mates anymore, I really rely on my girlfriend as someone who I can talk to, hang out with etc. I couldn't imagine life without her, but I'm not sure if that's because I'm just scared of being alone if I dump her (since my friendships aren't that great), and maybe there's other girls out there who could take that role in my life?

Instinct is what should guide you. You should instinctively know if this woman is right for you. We all learn from personal relationships whether they last or not. You shouldn't just dump her because of your neglected relationships with your mates, after all, if they were real mates, they would ok your relationship with this woman and you would be able to 'talk' to them as well. Remember, when the right woman comes along, you'll know it....no ifs or buts about it!