I just don't understand..

How do you trust birth control and condoms. I always feel like I'll be that 1-2 percent chance that gets pregant and then I terrified because I'm not a stable person emotionally or financially to raise a child. I get depressed and worried. I see women on this app using just the "pull out" method and in awe over it. I just don't get it. How do you know it's working? What do you do if end up pregant against your wishes? I'd just like some advice how to get over this paranoia. It's annoying and I can't enjoy life.