whats wrong and how can I fix my '91 Honda accord?

My car is dumpng white smoke out of tail pipe and struggling in idle. It sometimes dies in idle. This started after a long drive on freeway and car overheated. Car already had tiny crack on top of radiator and map sensor problem, had to step on gas and try a few times to start but once warmed up would run and idle fine. After overheating problem started. After dying in idle a few times at red lights the car will die and not start again unless it sits awhile, at least an hour. After overheating on freeway had to tow home and let sit overnight to start it again. Im worried I cracked a head or something of that sort, can anyone tell me whats wrong with my car?