How many mikes has it done?
Need to start with the ATF fluid, get it replaced.
Check your MAF sensor, if it's poor it will cause the gearbox to malfunction. Don't forget the gearbox needs information from MAF to function effectively.
The aftermarket bluetooth accessory u installed might be conflicting with the gearbox module. Yes there is a TSB on that! U may try to remove it and see if it help.
Last but not the least plug a scanner on the gearbox module and see if there is a fault code.