I erm, I have this thing where I think about swallowing a bottle cap or some sort of object and it’s worrying me and I just want to live a normal life but I can’t with this worry
This is unusual. Look out for professional help. As per your Tag, it says Depression then research about some good therapists so that they help you and take you out of this.
Links are also provided on this website. Have a look. 💛