One of the things I do is to take a strip of soft cloth and literally tie it to the top of the tent so it's supported... this won't/doesn't harm the bud and you can keep it going until you're ready to harvest. If this isn't an option, you can always put a long-enough stake in the pot and loosely tie it to the stake... ANYTHING to give it support that it's crying out for! Don't give up on it!
Sounds like it's going to be a great harvest - some people would kill for such a heavy bud!