Motivation to write?

Im one of those readers who only read 50K+ fics because i love development and a nice long story to chill with. Im very passionate about a fic I just started writing (only 8k in) but i keep thinking about how big ive made the plot and it seems kinda daunting to write.

Its a harry potter fic so it is ofc gonna be quite long, and it doesn't help that i don't like time skips 😅i rlly wanna write but whenever I open the tab, I just remember how many words i have ahead of me. I like finishing a fic before posting bc i have a history of starting stuff and abandoning it 🥲

Does this happen with anyone else? If so how can I find the motivation💔