Try going to the gmail website and change your gmail password. Then go back to the phone and reset up your account.
If you decide to do a Factory Hard Reset:
Perform a hard reset on your Droid 2 if you wish to wipe all the data from the device.
1. Turn the Droid 2 off. If it’s frozen and you cannot turn it off, pull and replace the battery.
2. Open the keyboard and press the X key while pressing and holding Power. The device will power on. Keep holding the buttons downuntil a yellow triangle appears.
3. Press the Search key on the keyboard (magnifying glass).
4. Use the Volume Up and Volume Down buttons on the side of the phone to select the Wipe data factory reset option. Use the Camera key to confirm it.
5. Tap wipe data/factory reset then tap OK.
6. Highlight reboot system now is highlighted then tap OK.