How to REALLY believe “it’s already mine”

This is probably the biggest thing I struggle to comprehend or accept. Small example from today: I entered a skincare giveaway from a brand I really love. I’m never won anything, though I’ve noticed my brother often does, even if they’re just very small things. In fact, one time he and I entered something together, and we won it—I think because he has developed the belief that he’s a winner, through his own experiences of this. Now, this got me thinking today. In the background of my mind my thought was “yeah right” it’s like it just knows it won’t be me. So I tried to change that thought into, this is mine, I’m a winner with or without it. But my mind gets stuck on the “it’s already done” part. I don’t understand how to believe something is mine when the 3D shows otherwise, because my brain says “delusional.” Any tips or wisdom on how to work with this as someone who typically overanalyzes and struggles to believe would be greatly appreciated! I know it could be as simple as just choosing to believe, but how do you believe when it’s not manifested in the 3d, and may not manifest? Like if I don’t win this, is it simply because I didn’t believe enough? Or how do you perceive that in a helpful way?