I want to be a big strong fat dude
Why do you want to be a big strong fat dude?
I want to be so I can feel confident
I am glad that you want to confident and strong. It is not healthy to be fat though, so be careful about how much weight you put on.
So what? I'm going to carry on being fat.
I don't think that's a great idea. Why not just be big and strong instead? Though, you can still be a bit overweight and be relatively healthy, as long as it is proportional to your muscle mass.