Ok so what you would do (I assume you have a new phone by now) is to take your battery out and hold the power key for about 30 sec. Then charge it for whatever amount if time seems good for yoyr phone (btry % might pop up too so that will help) onece yoyr phone is charged sufficiently, boot into download mode, and do a full wipe of the system. Once that is complete, try flashing the firmware again. If that fails repeat the process but this time wait to flash... idk why this works but my phone did the same thing and i was able to fix it after leaving it for a while. If THAT fails, try doing everything above but instead, flashing the stock firmware that you had for your phone. Be sure you leave it in a place that the cord wont be disturbed for like 30 mins. After a while ODIN should say pass in a green box and everything should be good. Dont worry about booting it for the first time, it is always slow, this is because the newly installed firmware is setting everything up on your device. but, if all else fails, sometimes, you break a phone in such a way that it cannot return from what you did to it... i really hope i helped you figure this out.