help me with my grammar, pls correct

[downy]

i did that thing to prove something and now i got it. you can't live without them...

[Francois]

Looks ok to me, though you want to capitalize "I" (I did that thing...) and the first word of the sentence (You can't...)
Got it = understand (is this what you meant?)

FRC

[Irma]

i did that thing to prove something and now i got it. you can't live without them...

what will you say about this one?

i have done it in order to prove smth and now i have it. you can't live without them....

i think from the grammatic point of view this is closer to the meaning.
wait for the comments.