Trouble with 16 GB iPhone storage?

I have an iPhone 6 s with 16 GB storage. However I recently just cleaned off 900 pics (backed them up on my computer finally) and started taking photos and videos on my vacation. Suddenly it's giving storage warnings left and right. I don't have that much. A few random apps, 200 songs, 3 pics and about 10 minutes of video. I don't see how this is happening. What can I do to fix this?!

Delete some apps that you don't need.

200 songs and videos take a lot of space. Look in your storage settings to see what's plugging it up.