[He's honestly thinking he may throw up at the very thought. Parasites? and they're still there! Now isn't the time to fall apart, though. He's horribly worried, and first things come first- making sure Lavi is and will remain healthy.]
We have to get them out of you. Even if they aren't causing problems, they could at any time, so- ... so let's focus on that, and then...
[And then- what? He isn't from Lavi's world. He can't help at all outside of this place, so he's determined to do everything he can here- even if he does want to find a way to save him from this. To save both of them- all of them.
Maybe if he thinks hard enough, he can save his own Lavi- wherever he is.]