I need to hurry, I know that kind of feeling well.
Tbh, I think the Julia we read is not "not Julia" but the real Julia. So, maybe the 1st Julia that got drugged died and reincarnate in Seoul. She went through her life in another world without remembering her past life, and when she dies she returned to her world, now with the memories from her other life because instead of reincarnating from baby, she went back to the time before her unreversable dead.
There a lot of Manhwa with that trope, with the MC actually come from the world they reincarnate because of some sort divine comedy.