I am just curious. You mention "if you commit suicide, then you might return as a centipede". I have been thinking about it, and never read in Hindu Scripture that suicide gets you punished into animal life. So is this certain?
Why you think suicide would make you an animal in next life? You don't harm anyone.
It's just my twisted sense of humor at work. When I was "at war" with a relative I used to say I hoped I'd come back as a poison mushroom, work my way into her spinach salad and giver her liver failure. Now that's nasty.