I maxed out my stamina, took an Endurance+, and a Super Viagra, and let the game go on auto fuck for like 2 or 3 hours (real time) until I fainted, and my ejaculation count went up by roughly 300. Still didn't get anything related to the too much cum ending. How do you get this ending???

Too much cum is gotten when you have a certain amount in you, you know the "you can cum (x) times" if you want it you must use endurance plus and walk untill you are feeling very healthy again, repeat untill you get it(at about 60 you get a warning scene and lose some cum, then if you raise it to about 70, you get the ending)