Worried about miscarriage!

I'm around 5 weeks pregnant and have taken a test everyday for the past week since I found out to be sure my hcg levels aren't dropping. I have anxiety and this has just become a way that I ease my fears. I am so worried I am going to miscarry or that the baby will stop growing and I won't know until my appointment in about 4 weeks, because this happened to my sister in law. I don't know what to do or how to stop worrying. Does anyone have any suggestions?