Have you got the custom recovery installed? If you have we should be able to fix things from there.
Can you tell us exactly what you did up to this point? It sounds like you've messed up the ROM somehow, but any info that gives us a clue may help.
If the custom recovery isn't working then if the bootloader is unlocked you can still flash one.
If the bootloader is locked and you have no custom recovery then it's either factory reset or RUU (for the latter we'd need to know what network you got the device from, or what region if it's an unlocked model).
It's fixable one way or another, but more info will help us find the best way.