If you wanted to die,you should think that why you born this

you 后要加were
这是一个宾语从句,think 后面是由that引导的宾语从句,疑问句要改成陈述语句,即系要将be.动词从前面放到后面.还有,this world 是状语,前面要加 in
就比如说把why were you born in this world 这个句子放进that 后面,然后were 就要放you 后
至于这里的born 不是被动,而是过去分词作形容词,所以应该是有were的.还有,这里的be.动词一定是用过去式的,就像I was born 一样,没有I am born 的

你想寻死，你就要想想你为什么出生在这个世上？
You want to killing yourself, you have to think about why you are born in the world?
这是有道词典翻译的，你可以参考。
我个人认为出生不是由自己做的决定，是被动。你是be born的。所是
why you are born i...

不需要。保持原句就可以的。