did you buy the lock upgrade? That one, then the one after that is the end of the game. it's confusing because it literally looks like it's locked out. those bastards lol. I don't know if the cycles of auto aim ever stop, it's just a crazy joke heh.
I accidentally left too, but it saves your progress if you choose 'chapter select'. Also, I never bought the buy/disable lock on stuff. It's just there to fuck with you. Go underwater, if I think you are where you are. Everything you need is under there.