I think you having a sober mind has opened up a gap, A space that has traditionally been flooded with alcohol. Now suddenly the gap is not being chemically filled, so your mind if finding things to fill it with. Nature abhors a vacuum. It's only natural you have regrets from the past, and they'll not magically disappear, but you'll develop an acceptance about them a little bit at a time. One day you'll look back and see the old you as a totally different person and feel that you have lived two lives. Happy days ahead!