Doctor Who Episode: "Father's Day"

In this episode, Rose asks the Doctor to travel back in time so she can see her father, who died when she was a baby. They travel back to the day he died so Rose can comfort her father while he dies. She remembers her mom telling her when she was a little kid, how no one was there to be with him after he got hit by the car, and he was dead by the time the ambulance got there. They watch him get hit the first time and Rose just runs away. So they go back again, and watch the collision again. They have to wait until the original pair of them run off to do anything. Once the original Rose runs away though, Rose runs out in front of the car and pushes her father out of the way, saving his life. This of course, changes the course of time and screws everything up. Rose then goes with her father to the wedding he was on his way to, where she meets her mom (who thinks Rose's father is cheating on her, with Rose) and herself as a baby. Then bad things start happening. Weird things that feed off rips in time, descend upon the earth and consume all the people in it. The doctor gets most of the people from the wedding safe in the church. He is trying to solve the problem and strange things start to happen. Like getting phone calls from the past,which shows that time is all meshing together, just because one man survived that wasn't supposed to. Besides that, everything is going fine, until someone lets Rose hold herself as a baby. This creates a huge paradox that lets the creatures in the church, and they kill the doctor. With no one to lead them, Rose's father now realized that this all happened because he was supposed to have died by getting hit by the car. He sees that car driving around outside, disappearing, and reappearing in the place it originally started, and driving again. He runs out in front of the car, and Rose holds his hand while he dies. It then flashes a little into the future where Rose's mom is telling her (as a young kid) that a blond woman whom no one knew had comforted her dad while he died, and then disappeared. And then, time is fixed. This idea of time travel I think is similar to Back to the Future, where you can't change anything major, like saving  a man who was supposed to have died, or making someone fall in love with the wrong person. But it is okay to change small things that don't majorly affect the future.