You can beat the game in 2 days in 5 easy steps:
1) Skip or watch prologue then immediately save.
2) Use saveeditonline and then give 9999 for all values
3) Now you can kill everything in 1 shot so you do the route towards the final map day 1
4) Day 2 play as your GF if you want or just immediately go kill that fucker
5) Get the same happy end as if you won the game between days 2-9
I guess you can take solace that canonically, if you beat the game in 2 days, she only sucked 1 dick (blonde guy IIRC) and got forcefully kissed twice or something aside from getting groped.
Doesn't matter anyways since after beating the game with any ending you get to play as her with max corruption + you can unlock all the OG scenes inside the scene viewer at any time. If you want all the "new" extra scenes I think you have to play through most of the days though. If you don't want to cheat you can only beat the game in 4 days min and only if you get lucky.