Was breaking up with her a huge mistake?

Is it possible that it could take breaking up with someone to make you realize she may be the one? I ended a relationship with my girlfriend of almost two years Friday night. It was the most difficult and painful thing I've ever done. We had a great relationship, had almost everything in common, and spent essentially all our time together outside of work. We still had our own apartments, but I hadn't actually slept at my place in about a year and a half. The reason I decided to end it was that I couldn't picture myself ending up with her. I knew she envisioned spending the rest of her life with me, and while for the most part I was happy with her in the present, there was a sense of impending doom building inside me because I knew I would eventually have to break her heart by ending it. I couldn't get this thought out of my head, and the longer our relationship went on, the more I obsessed about it. (I'm a fairly obsessive-compulsive person in general.) I think I even subconsciously started treating her a little worse (nothing terrible, but little things like running late a lot, not doing as many nice little things for her, not initiating "I love you" as much, etc.), perhaps in the subconscious hope that it would make her like me less so I wouldn't have to hurt her as badly. I'd pondered breaking up with her on and off for several months, and planned to possibly do it a couple times before but gotten scared and hadn't been able to go through with it. However, the moment I broke up with her, I began to fear I'd made the worst mistake of my life, and I've felt this way nonstop for the past two days. I keep trying to remind myself that despite all the time we spent together and all the moments we shared over two years, I was still never able to see myself ending up with her. But when I try to figure out what it was about her that was standing in the way of me seeing that future with her, I can't come up with anything. The only concrete things that bothered me seem so meaningless now compared to all her amazing qualities. To a certain extent, I was prepared to feel this way. I know breaking up always makes you focus on only the good qualities of your former partner. But when my last relationship ended (which was mutual), although I started to harbor false feelings of being in love as a result of missing her, I was always still able to bring myself back to all the reasons she wasn't right for me. This time around, I can't seem to do that. I've been trying to tell myself that a lot of what I'm missing is the comfort of having someone to share my life with rather than specifically her. But I can't convince myself this is the case or envision myself being as happy with someone else. I wish I could write my prior concerns off to a "fear of commitment," but I don't think I've felt afraid to commit or scared of the future. So essentially, the reason I broke up with her had nothing to do with the present, which was going great. It was all about the future, not being able to see myself marrying her, knowing this meant I had to break her heart, and forcing myself to do it now since it would only hurt her more if I continued to wait. But now that I've broken up with her, spending my life with her is the only thing I can think about. I've barely been able to make myself get out of bed or even function this weekend because I miss her so much. I guess my question is this: Is it possible that it could take breaking up with someone to make you realize she may be the one? The people I've opened up to about this keep telling me no, that I'm just sad and lonely and confused right now and it's making me feel things that aren't true. But is there any way that could not be the case? Is it possible breaking up with her was something I needed to do to help me become able to envision a future with her?