Undergraduate / "I've graduated from university" - Help in correct a short paragraph. [2]

Hi,

My name Ammar I'm new here and I'v been in US 2 months ago, I am taking a writing class, can someone help me please to correct my short paragraph. I know I made lot of mistakes.

thank you

I guess my greatest achievement will be when I've graduated from university. It took me
five years to finish it.
I was working at night and going to the university next morning, it was hard to stay up for 16
hours. I remembered sometimes I stay up for 20 hours to get done with my homework or my
working, I didn't have a normal life like my other friends, I was busy in my college and my
work, because I believe that one day my hard work and my study will gives me something good
in my life.
Those two things encouraged me to come to United States; I have ability to continue with my
study and pass all the difficult circumstances in my life.
In fact, no matter who you are, if you believe in yourself, you can achieve all you goals and
make your dreams come true.