Hi
Apple advises that you should not continue using a damaged iPhone.
As your iPhone was dropped and suffered damage, I suggest that you contact Apple Support (mail-in service may be available), make a Genius Bar reservation or visit an Apple Authorised Service Provider to arrange for it to be inspected and to establish your available service options, timescale and cost:
- Contact - Official Apple Support
- https://twitter.com/applesupport
- http://www.apple.com/retail/geniusbar/
- https://locate.apple.com/
Apple's price for a screen repair (if that is all that is required) for iPhone 5s in the US, for example, is currently $129 plus tax and, if required, shipping:
iPhone Service Pricing - Apple Support
Note that, if you have the screen repaired by anyone other than Apple or an Apple Authorised Service Provider, your iPhone may no longer be eligible for any future service from Apple (including chargeable repair).