Even if you are not the main writer anymore, you could still proofread from time to time to ensure that the story, characters and flow follow what you originally intended them to be. I think this is a more efficient way of doing it if you aren't confident with your own writing skills yet plus the fact that you had to spend a considerable amount of time on the art.
I love this VN and I hope you get to successfully complete it just like how you envisioned it.