plug in the charger and wait for the battery to completely charge. then unplug the charger, and plug in the usb with the power off. press and hold the home button while turning on the power.

if you have the charger plugged in, it is not completely powered off, so you wont get into the flash mode when powering up.

you may have partially flashed the device, which should be correctable. the term "bricking the device" usually refers to a completely defunct device that doesnt respond at all. i dont think you are there, yet.