Q: Car won't go over 2rpm or 15mph after it died. Have a clue what it is?

It is possible that your battery is just too weak at this point to handle the extra power that higher RPMs demand. More power is required for the fuel injectors and ignition components. Try charging the vehicle for a long time before test driving it again. The alternator maintains the battery and is not designed to charge the battery. Much like a cooler will help maintain a cold beverage, but will not make it colder if its warm without help from ice. If you are still having trouble, I suggest having a certified technician, like one from YourMechanic, determine the exact cause of the stalling issue.