Is there a novel for this?

Yes. It's complete.

yes. i read it here. https://ateliersolaris.com/novel/follow-your-heart/

what chapter should i start if i want to continue from the latest manhwa chapter

i'd say to start with chapter 59, as that's where roderick helps lee-jae make the medicine.
https://ateliersolaris.com/novel/follow-your-heart/1/chapter-59/