tranny

So I have a question I got into a car accident the front passenger lights and stuff weee damaged a couple days later the car started messing up I will be at a light and the car wouldnt go so I would turn it off then turn it back on and it would start to go. One day I was drivint and all of a sudden I am the light and it wouldnt go even after I turned it off then on and tried to go. The car was on but its oike it wont shift into gear. I had a leak in the transmission so I would put tranny fluid in every so often this time the car wouldnt start I tried to put trabny fluid in and I overfilled it. Can u tell me whats going on please.