Q: Drove in manual on accident on freeway for 30 mins.

Hello. It is likely that one of the lower gears were damaged when the transmission was stuck in manual mode. I’m guessing that the gear that it drove was first gear until you got to your destination. Driving in first gear at freeway speeds would produce major mechanical stress and the highest heat in your transmission. It is likely that the vehicle will need a new transmission but you could try to do a transmission fluid exchange first because that may help. The extreme heat which was produced while you were in manual mode would be high enough to break down the fluid, making it require replacement. Transmission fluid is one of the most vital things in the transmission and a fluid exchange is the most feasible transmission maintenance option. In my opinion you likely need a new transmission unfortunately. You could have it rebuilt but rebuilding will probably be more than a transmission because the first gears are all the way in the front, meaning they will have to tear apart the whole transmission to repair those gears.