The amphetamine molecule enters the neutron and does several things, two of which are:
1) Force dopamine that is in storage in the neuron to be released prematurely.
2) Reverse the direction of the dopamine transporter so that free dopamine within the neuron that hasn't been reclaimed yet is forced back out into the synaptic space. Usually the transporter moves dopamine from the synaptic space back into the neuron.
To restore dopamine levels you'd need plenty of rest and a healthy diet. Forcing the brain to use the last dregs of dopamine it has left with drugs would be the worst thing you could possibly do.
Edit: In short amphetamine doesn't replace or substitute for dopamine, it just forces the brain to use what it already has. If you're running low it's going to mess you up.
But, I can think of no /quicker/ route to some sort of intense crash and possible health issues than using a constant diet of sugar and speed to push oneself beyond their capacity day in and day out 24/7.
The author of TFA simply didn't run out of glucose as he claimed. The symptoms from that are entirely different than what he described.