Although the phrase "It retains its alignment and personality." should include your class level, subclass, feats and life experiences, as these are what has formed your alignment and personality. To not have them sounds pretty stupid, but there are really petty people who DM and rule on such stuff. They want you to act like that person, without any of the things that made you that person. Pretty weird logic they want you to believe.
There is a semi-simple solution for this, the 5th level Modify Memory spell. Best to prep a written list of Class/Sub-class, their abilities, your highest level of spell ability & highest level and number of spell slots, list of feats and any relevant choices (like fire for Elemental Adept), list of major events you were part of and list of friends, enemies and significant acquaintances you know. The spell specifically says “…its mind fills in any gaps in the details of your description.” So, have a friend cast it, read off the list, hold the spell for 1 minute, and all those things are recalled, your mind fills in the gaps (not hard as you lived them), and "POOF!" you are restored.
For qualifying for the spell, the 6 second event of the changing at casting qualifies, if you cast this spell after the initial hour (so it is permanent) but before 24 hours expires, it will be within 24 hours and they will "allow the target to recall the event (the losing of their memories and abilities in 6 seconds) with perfect clarity and exacting detail" while “its mind fills in any gaps in the details of your description.”
*All that being said, if your ability or feat is race related/required, you will lose it. Since we don't have a decent or generous DM, requiring us to use this spell to solve the problem, it is highly unlikely they will let you keep these feats, no will you get replacement one(s). They will be lost.*r