My earphone hole won't work on my iPod touch

Ok, iv had my iPod touch 4g since last Christmas and it's been working fine but about a week ago something somehow got wrong with the earphone hole because my earphones won't snap in the hole it goes all the way in but doesn't click in. The music doesn't play through them because it doesn't snap it. My friend told me that it could be from plugging it into a car jack. But I don't know. I thought something was maybe in it but there's nothing stopping it from going in. I looked inside my friends and theirs had a little silver thing at the bottom and mine doesn't so I think that's why but i don't know why it wouldn't be there anymore because iv been using it before my earphones just wouldn't click in the hole. How do I fix it? What's wrong with it?