This is an amazing write, and such a good message.

A few critiques;
second stanza;
'those too younger' - remove the 'too' it's unnecessary and a little confusing with it there.

third stanza;
'all what's remaining' - change the 'what's' to 'that's' I think...

third stanza;
'oxygen in lungs' - I think that needs to be 'in your lungs'

Also, I think some more punctuation is needed in some areas to give pause to ideas before the next.

I particularly loved your fourth and fifth stanzas - they seem to be the peak of your poem and do all the explaining in themselves.

Well penned. 5/5