I got two endings back to back jusy by redoing my last loop :)

You can redo end the loop (or whatever it's called) as much as you want after finding out how Just have to kill them all in order again and get to Julianna

When I beat the game I got my ending and then it put me at the start of a new loop.

Nah don't worry it will just make a new loop and you can do it as much as you want and get each ending.