hindi basta basta nasisira ang Automatic transmission. if properly maintained.. the clutch pack won't be destroyed unless the tranny is abused or misused.
the torque converter is just a cylindrical area with vanes inside for the ATF to travel thus creating the torque...
mahirap sirain ang torque converter lalo na kung everyday car mo lang naman ang vehicle...

what is easily destroyed or could malfunction are the valve bodies and the solenoids inside your transmission ...
using an incorrect atf, low level and over-filling could also cause problems in the long run for the transmission...

I suggest you bring your vehicle sir to an "automatic transmission specialist"
mahirap ang "hit and miss approach" dahil mahal mag pa repair...

anu po ba history of the vehicle para mas makatulong po kame