how do I go back to the game from 'memories' without starting a new game? It's not letting me go back to the main game and I wanna play more of my original run
The arrow pointing to the left (on the top left of the game's screen) can reroll you back a few pages that maybe can save you (depending on how long you've been in the gallery/memories).
Other than that, there's no other choice than restart. You technically finished the game by going to an ending and then to the memories.