我觉得或许可以翻译成"如果我那么做,我将会令自己成为失败者"

如果是我做的话，我只需做好失败的准备。 or 如果是我做的话，我将做好最坏的打算。 This sentence tell u that if u want to be succeed,the only thing u need to do is relax ,take it easy and prepare for accepting the failure. 调整心态，做好失败的准备。Anyway,attitude is everthing.

若我做了那件事 無異於將自己推入敗局 若我做了那件事 那就是自取滅亡 若做了 就準玩兒完了

I am not sure whether 'set oneself to fail' refer to: deliberately not to make any effort to suceed since you know it is too difficult or you are in a very awkward situation If it is, then you may say: 如果我做这件事，那我就破罐子破摔(a bit informal) 如果我做这件事，那我就放任自流

There are many ways to say it in Chinese, I would say "如果我那么做，我是存心想以失败收场"