I would give anything to not have OCD

Got an iPhone 14 to replace my current phone, an Oppo, that's cracked and doesn't work properly. Super chuffed about it but I've convinced myself that using it is going to make me gain weight and become almost a whole new person. Currently freaking the hell out because I'm so stressed about this. Please please please give me some advice or anything on how to deal with this. Thank you ♥️