Alternater wont charge battery and fusable link on starter keeps burning

You have a serious high voltage short circuit that not only has burned out the fusible link but probably killed your voltage regulator and alternator. Did you replace your starter? check the wiring of all components ..alternator /starter.. ground cables /positive cables. check for chafing and melted wires.. You must find the short first because if not you will simply burn out another component.

·Make a simple test of the alternator:
If you can, somehow get the engine running, measure the voltage at the battery. It should be at least 13.6 volts to properly charge the battery.

Bad voltage regulator. Usually built-into alternator.
Start car and unplug battery, if it dies your alternator is dead. Get new alternator. If car keeps running, get a voltmeter and check voltage coming through - should be higher than 12v but less than 18v. Any other number means your voltage regulator is dead, cheaper to get a new alternator.