Maybe try saying you missed so.many meetings because (make something up) or life got in the way but now you no longer recognise the religion as the one you once belonged to. The "truth" being taught now compared to the "truth" you taught has changed so much you need time to study and catch up. By the way, can you explain the over lapping generation thing cos I am really having a problem with that one. (Substitute overlapping generation for blood fractions, the resurrection of Sodom and Gomorah or any other doctrine you know they have flip flopped on).
I am faded in a new town too (only 8 miles from my old cong) but still not bumped into anyone I know in almost 10 years.