hair growth stopped?

Hi I have a problem where my hair seems to have stopped growing. In the last 6 months it hasn't grown at all. Its exactly half way down my back and I am really sad, I really want waist length hair more than anything, its like my life goal. Is it possible for hair to stop growing and start growing again in intervals? Anyways if I have to I will cheat the system and get hair extensions. I eat really healthy and am really really athletic. I have had a buzz cut my whole life so I have no idea if my hair can get any longer. Any advice?
I am a 22 year old man 173cm if that matters.

Hair does tend to grow in cycles. Hair follicles tend to grow for about 7 years before they shed and regrow again. During that time, the hair may experience a retard in growth just towards the end of the hair cycle. If it has indeed stopped growing, there might be other factors contributing to this as well. If you are not properly conditioning your ends, you could be experiencing some breakage at the ends that will make it appear as though the hair has stopped growing. Try to condition your ends thoroughly as well as stimulate your scalp.