had to create a new character and delete my first Coc2 character
There's a whole 10 save slots, plus an extra ten autosave slots, and the capability of backing up your saves outside of the game by saving to desktop. So, were you only saving your game in one single save slot, or perhaps only two (I do that often, but that's because I have like 18 different characters split among Chrome, Firefox, and download game version, along with saves made to desktop for characters who's in-game saves were then deleted for space)? You said it was your first CoC2 character, and you mention having to create a new character afterwards rather than deleting and swapping to an alternative character, so the saves wouldn't be competing with other characters. So, that means that, despite ten different save slots and no other character to take them up, you were only saving in one single save slot.
Also, you didn't think to check the autosave slots. The autosaves happen on a scene transition, with a cooldown timer of 15 real life minutes (or something like that, you can adjust the time in settings) between them, so unless you proposed, went off and did like 5 other quests (aside from the Centaur Village quest, I'm fairly certain the proposal happens at the start of the dungeon), and then came back to do the marriage scene, I'm fairly certain you could have loaded an autosave that happened before you proposed to Ahmri.