My bruised toenail is coming off!?

its been about 4 or 5 months since i bruused my toenail. it bruised on the nail bed and turned black and since then the top layer has just been breaking away from the base of my nailbed in an arch shape. its about midway through and theres another hard layer under the first nail thats breaking off. im starting to get worried because now the black area has become loose but the tip of the nail is still normal color and seems to still be attached. i put a band aid over it but i think its coming off and i dont know how to deal with it. please help.