I won't let myself relax!!!!

This is my first pregnancy and I am worrying constantly!! I just had an appointment last week at 15 weeks 1 day and heard the heartbeat! We go back March 11 for gender scan. But I still keep finding myself paranoid. Googling missed miscarriages, crazy stuff. I am supposed to go shopping with my sister tomorrow for gender reveal party stuff and I am terrified to shop and enjoy my baby. I am always overthinking everything. Someone help me relax!!!!