I thought about it quite a bit in early days, I think that's part of the obsessive brain in early recovery. That spinny thought pattern will die down in time. Add to it that you're in rehab and it's larger than life.
Time takes time. Someone told me that at about two weeks sober and it was really comforting to me. The longer I'm away from the bottle, the less guilt/shame/regret I feel. I now see that I am someone in recovery from alcoholism, not an active alcoholic. I see nothing wrong with that. That's where you are too.