"Quirrel is an inquisitive, up-beat explorer, fascinated by the myths of Hallownest for reasons he cannot explain. While he remains a simple observer, he is wise of the land's dangers and has some skill with a nail."

Quirrel throughout most of the game is [perfectly healthy]. Little does he know he's lived over two lifetimes, and the mask he wears acts as a life support system, keeping him athletic and spry (he does not know his mask is doing this, however). When he gives away his mask to its original owner, the life support system is no longer helping him, and [his body suddenly starts failing] (legs buckle, voice rasps). He then used his remaining energy to travel to the Blue Lake, the final sight he wished to witness before leaving Hallownest. Here, the player and Quirrel spend their last moments together, and Quirrel is [close to passing away]. At this point, Quirrel is at peace, accepts his fate, and is thankful of the circumstance he was given.

Hopefully this helps, but if you need to see more character interactions with Quirrel, this video https://www.youtube.com/watch?v=Z5GinwEoTPo shows exactly that. Please do your best to match your voice to the voice and pacing of Quirrel's, and to make sure each line matches the correct circumstance they're said in, as seen in the reference video at the top of the project page.