How the heck are you saving all of this? Do you leave GTA V running or is there a way to save outside of autosaves and safehouses?
the game pauses when I open the steam overlay, also yeah I do keep it running
you fell because you didn't have happy thoughts going through your mind
think about milk to fly
you think extremely hard about that milk

well this isn't anything to do with flying
the milk is at the top of that large mountain. you must now hike up the mountain on foot to reach the milk.
you decide to use the recently spawned bike instead because it sounded like hike, perhaps this bike is infused with milk?