Nexplanon scared

So this is my first birth control and the doctor almost literally begged me to get it they kept saying birth control this and birth control that so I said ok well I got it it’s in my arm and I just started having some faint but Definate side effects like eye irritation some back pain etc someone please help I’m already concerned about my health enough already and I can worry myself and I feel my body will cause all of it by me worrying