This is a simple addon that will allow you to toggle between targeting yourself and your last target. Useful if you like me don't like to use modifier keys to heal yourself and would rather switch targets and then switch back to your previous friendly target to continue healing.
Type /shtb to set the hotkey you want to use.
Big thanks to Viper for helping and letting me use VLib and Tsulong for having some handy hotkey code in his Healie addon.