<human>: We've been dating 2 years, and have been drifting apart for the last 6 months or do since she moved about an hour and a half away.

But in reality I've been unsure about this relationship since she went to rehab for alcohol about a year ago. (she's still clean btw) I didn't break up with her then because I didn't want to make a difficult time worse. I do love her but I can't see her as my lifelong partner. I've come to realize that she wants to move forward in our relationship, move in together, probably marriage and what not and I don't. Not with her at least. 

If we stay together I'm just going to be stringing her along until I find something better and that's not fair to her. I know it will be painful for her but it'll be worse if I keep it up. 

So I guess the question is, how should I go about it in the most painless way? I have always been bad with break ups.

Can you succinctly summarize the text in 1-3 sentences?
<bot>: been with someone 2 years. It's not working, she doesn't know. Want to gently break up with her and need advice.