想問一句中翻英，我這樣翻對嗎！？

Supposed, one day I were recovered but that wasn't myself before; then I'll let you disappointed as being felt down and disappeared. Yip

你寫的太情感豐富，用詞亦有很多可能的意思，因此甚難意釋英文，但直譯英語便如下：

如果我有一天恢復正常了，我將不再是原來的我；
If I recover one day(或one of these days - 假如預計是漫長的康復之路), I won't be myself as before. [英語較常說：I wont' be the same anymore/no more]

如果我倒下了，
If I fall [指跌倒那種倒地] / If I fail [指失敗] / If I died [指死亡]
但假如是指意志的倒下...(假設性修辭)
If I were beaten / If I were defeated / If I were dead,
我將會消失。
[由於前後句的語意不太明確，因此只能按字面翻譯]
I will disappear. [意思是在現場/當場消失]
I will vanish. [意思是在退隱]
I will be no more. [意思是煙消雲散/灰飛煙滅=死去]

對不起，讓你們失望了。」
sorry, I've let you all down.
sorry, I 've disappointed you all.

感覺太悲觀...

如我有一天恢復正常了，我將不再是原來的我

If I could resume life activities(or return life to normal)one day, I will not be the old me anymore.

；如果我倒下了，我將會消失。對不起，讓你們失望了。」

If I fail to pull myself together, I will disappear.

對不起，讓你們失望了

I’m sorry to let you down.

如我有一天恢復正常了，我將不再是原來的我
If I could get back to normal one day, I won’t be what I used to be.
如果我我沒成功(手術嗎?)，我將會隱姓埋名。
If I couldn’t make it, I would incognito(隱姓埋名).
對不起，讓你們失望了
I’m sorry that I let you down(disappointed).