Help with my job

So I’ve started a new job like a month ago but I’m really unhappy with my hours it’s care Work and I stupidly put I can work any hours but meant like 3-7 or 9-5 but they are literally having me work from half 5 in the morning till quarter to 12 at night half of the time I don’t even have a break because by the time I’ve walked home I have to go again. It’s making me unhappy and I never have anytime to myself I want to change my hours but I have extreme anxiety and I’m scared to talk to the people i work with. I don’t want to get shouted at or fired. How can I go about changing my hours? Because I feel bad changing it because they have already give me a set rota for next month so if I change it means they have to find other people for it.