Sounds like a problem with the ignition. Take it to an electrical shop or if your handy make sure your getting power to the starter. Ive seen lots of loose battery cables that cause problems. Also maybe when your belt broke it caused damage to something, fuel line, battery cable. Does the starter solenoid spin or is it just dead? Is your battery charged. Is your alternater charging. Put a volt meter on the battery when not running, the voltage should be around 11.5 to 12 volts, then start the engine and if the battery is being charged the voltage should be around 13 to 14.4 volts. If its not that high you should replace your alternater. It is probably something very simple.