I feel similar. I did love her. But, I knew she wasn't someone I wanted to spend the rest of my life with. Now I'm 2 years later still alone, still remembering the good things about the relationship. For me, its the fear that I made the wrong decision. I think that I know I did, but the fear is there. Some days it hits harder.
The other reason is, I'm still alone. I live in a small town; no friends within 5 hours. I don't have that boost to my ego that I am desirable anymore. I don't have the support from her anymore (even though it waned in the end).
I still keep up with my friends online nearly daily. It helps. We all met up in Texas for a buddies wedding a week ago, each of us flying across the country. I was happy then but, going back home was definitely hard. I already miss them.
Overall, I think I miss the comfort of holding someone or being held by someone that I cared deeply for and them for me.