We don't recommend trying to unlock your own phone unless you REALLY know what you're doing, exactly for this reason. If you enter the wrong unlock code too many times, you'll lock the
SIM and might as well throw away the whole lot.

I highly recommend before you do anything else to that phone, take it to someone who knows what they're doing and ask them if it's too late, did you already fry it or can they unlock it for a small fee.