It's likely i've damaged mine right?
You haven't done it any favors. It's not difficult to create a voltage divider, using 2 resistors so that the device can be powered by a digital pin.
pin (5V) --> R1 -+-> R2 --> gnd
If R1 is ~3K and R2 is ~6K, the voltage to the adxl3xx will be ~3.67V. Make R1 a little larger or R2 a little smaller to drop the voltage going to the accelerometer. Measure with a voltmeter to be certain. Compute the current flow for you resistors to be sure that you don't exceed the current capabilities of the digital pin (40mA max; 20mA recommended). Make sure the resistors can handle the current flow, too.