@datnguyen :-
You're getting upset, over-excitable.....and you're panicking. None of which help when you're trying to fix problems.
The fiirst thing you need to do is to kick back and take a break from this for a little. Get away from the computer.....go for a walk, head outside and get some fresh air. Do anything you like.....but get away from your computer for at least an hour.
It won't go AWOL if you're not sitting there, but it'll give you a chance to calm down, and clear your head.
Now:-
What you need to be aware of is that for any Linux "noob", re-installing operating systems over & over, again & again & again is
perfectly normal. This is all part of the Linux learning curve.....figuring out
what works, what
doesn't, how & why things do
what they do in the
way that they do it (rather than
some other way), etc., etc. We've ALL been there, bought the T-shirt, worn it out and replaced it, and come out the other side of the tunnel with at least a vague idea of what we're doing!
None of this happens overnight. It does require a certain amount of perseverance (AND a degree of enthusiasm - and determination!), but it IS "do-able".
We're always happy to help if it's within our capabilities.....but panicking & getting over-excited does NOT help.
Mike.