The cursor glitch

So I just bought the game on Christmas and I am up to season 1 episode 3 the train and I can't progress as the cursor only reaches the 2nd final sitch and I can't reach the final one on panel 6 I killed the zombie in the car grabed the chocolate gave it to duck then Lilly took the RV and now I am stuck and can't go back to the start of the mission please, please help.