...nhưng tôi đang thật bị bỏng nặng!
I’m not even sure what you wrote...
Oops. Now that I look at it again, it doesn't make much sense. I just put it into Google Translate about a month ago, when I was worse with Vietnamese, lol.
It's supposed to say "but I'm very badly burned!"
You need cháy there instead of bỏng I think? And theo tôi, rất is a better translation of the use of 'really' than thật. Since 'really' is being use more as an intensifier than as an assurance of the truth of the statement. (I haven't gotten confirmation on my understanding of thật yet, but using truly has always been marked a correct translation so I think I have it right)