It sounds to me to be kind of like "shock" and a protection system. I did the same thing when I terminated a relationship of nearly 10 years, moved from my home of 13 years, left all my friends (at the old location) and changed jobs. For a period of 1-5 years, until I got familiar with all my new situations, I was kind of numb like you say, but not unhappy (I had some good things happening too; moved to be close to my boyfriend, now my husband) I just could "consider" things, couldn't go very deep in my head like I was accustomed to, couldn't tell you how I "felt". It was like I was locked out of the control room :-) but the factory was still functioning fine.

I would work toward therapy if I were you, as best you can. It was only 10 years later when I got therapy that I was able to understand that period and deal with all that had happened to me effectively and gain back all of my self.