I used 50% of my data for my iPhone 5s in 4 days! How do I help save the data?

I recently had a party and had pandora playing for about 5 hours. My phone was connected to Wi-Fi but it would keep changing to 3G because it couldn't stay connected to my Wi-Fi so I just kept fixing it. And apparently pandora is an app that uses a lot of your data. Also I watched YouTube videos for about a half hour before realizing that my phone wasn't connected to Wi-Fi. I got a notification saying that I used 50% of my data but it's only been 4 days since it restarted. I know this is a little ridiculous but I'm just freaking out because I've never come close to going over my data and I still have 27 days left. So how do I stop using my data?

Turn off lte

First thing is first, you should probably figure out why your phone keeps getting dropped from your Wi-Fi connection. Check your router or something maybe. If you can't figure that out and you really want to lock down on data, then go to settings>carrier and turn off cellular data. This will restrict all internet using apps and service (including email) to only Wi-Fi.

Well yea, any streaming app is usually considered a data hungry app.

Just don't use it or at least try not to use it as much for the remainder of the month.

Use Wi-Fi as much as you can. You can turn off cellular and turn on Wi-Fi, so thats all you can use.