Please don’t panic about situations like these! I have older stories that I tried to rewrite but I just didn’t have the spark for at first, don’t give up, I promise you that the spark will come back and that this is normal.
Some writers call it writers block, where you become uninspired to write anymore, but it doesn’t sound like you’re going through writers block. You will start getting back into the flow of this story, it just takes a little bit of time, you haven’t lost your talent and you haven’t degraded.
You will gain your spark back