I had the same problem last week while getting over a bad flu. I had eight performances in one day (each performance being no longer than 20 minutes). My voice was GONE by the fourth show. Luckily I had an hour break until the next four consecutive shows. I drowned my throat with warm tea and lots of honey. It got me through the rest of my performance....just squeaking by (pun intended). But my voice was completely gone by the end of the day. The only thing that I found as a cure was like everyone else said...REST! I talked as little as possible for the next few days which is REALLY hard if you knew me. I love to talk. :D I also felt it was soothing to wrap my neck in a scarf to keep warm. I don't know if that helped but it felt nice. I also periodically wrapped my neck with an herbal warming pad. I think the scent of lavender is always soothing to me...not for everyone.

So, REST....REST...and REST some more.
Now, if your voice is continued to be strained after resting and some time has passed, I suggest you see a doctor. You could develop nodules on your vocal chords. That is a very bad thing. A lot of professional singers develop them. Julie Andrews experienced this and tragically had surgery that ultimately ruined her singing voice for good. I am still saddened by this and I am always thinking of this incident when I lose my voice. It frightens me. I always try to go for a healthy voice (as my singing coach reminds me). It's very important to take good care of your voice. Perhaps thinking of a different voice for your puppet that is less straining is something you should think about. You know, Elmo didn't have the original voice that he has now. However, I can't imagine the current voice is a healthy voice choice for the vocal chords...lol.
Hope you feel better soon.
xoxo,
N