I was driving and heard a grinding/breaking sound; instantly the car wouldn't accelerate. I am thinking it has got to be the transmission, but I don't know if it is the whole thing, a stripped gear, or something else.
There is a good chance that what you heard was the transmission. Transmissions are very complex systems. It is very likely that the transmission will need to be overhauled or even replaced, depending on what part of the transmission has failed. I suggest hiring a mobile mechanic, such as one from YourMechanic, come out to inspect the grinding noise coming from your transmission.
Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing