iPhone 5 service problems after being dropped.

Hi.

So I know a lot about fixing iPhone 4's and 4s's but I've never opened up an iPhone 5 so I am not 100% sure what's wrong with my phone.

I dropped the phone last night hard on the floor and at first all seemed fine. But on closer inspection I noticed the service was dropping in and out constantly... First the 4g icon will disappear and then the actual service on the phone will go into 'searching' and then about 10 seconds later the service will come back on followed by the 4g. And about 10 seconds later it all starts turning off again....

Also, if I make a phone call the service will NOT drop! The service will stay on perfect and clear, but it mainly works on speaker phone. Without speaker phone sometimes I can not hear anything but 'fuzz' and the person on the other end of the call can only hear there own echo...

Can anyone please tell me what needs fixing? How bad is the damage? :(

Thanks in advance :)