I wish you luck. I've grown my hair out many times. I didn't have a mohawk, but I used to have the bottom part shaved all around and a few times I've had really short hair all over, like a crew cut, and grew it out. It's a pain, but it's worth it. Your hardest challenge will be to sit there and not cut it! I know, I used to work at a hair salon, so getting my head shaved again was a really simple thing.
Keep us posted, so we can give you some moral support if you need it.