easy fix! would probably be good to grab some type of garbage bag first but all you have to do is grab your iphone towards the bottom and while holding it over the garbage bag, just let it go, tie it up, toss it in the trash and then go buy an Android! haha....jk! is there anything stuck in the headphone jack if you look into it? I know this might sound dumb but its happened to me once but does your headphones have a volume control on them? could be turned down all the way?
well it's either the wire to your headphones or the input jack on your phone. try plugging them into something else and see if they work. also in your settings under music, check where the max volume is set at. let us know your findings.