Home alone

How do I get over anxiety about being home alone? I'm 22 and up until this point (I still live with my parents, my fiancé lives with us and our son) tonight is my first night EVER being in the house by myself, with nobody else here. Lately I've been having problems even just sleeping if my fiancé isn't in bed with me, but I have a full house other wise. I'm scared tbh. All windows and doors are locked and I have all the lights on. I'm an adult... I shouldn't be feeling like this 😭we are moving out in 3 months and Idk how I'm going to do it...