My iphone 4 says i don't have enough storage to take a photo?

But I have 5gb available on my icloud, 1.9mb available on my phone. I ONLY HAVE 43 photos on my phone right now! I used to have over 250 but I deleted so many! Also, I only have 16 apps. THIS IS So ANNOYING! How do I fix this?

Make sure you don't have any videos on it.
Also some apps that need more memory must have consumed the space. For eg GarageBand.