You are not a terrible Mummy. You are a great mummy!!! I do the same thing you do. I don't like to let Harrison cry either but I have tried the pulling over and giving him a feed or settling him, and I find it makes him worst. He calms down while I'm there but as soon as I put him back in the car seat he is 10 times worst. If he is too worked up I will pull over. I brought him a toy arch that going on car seats that seem to help. Portable dvd players are great if you have to travel a long way. Best of luck.