English learning, gotta help me please.?

Okay first off I am going to re-type your question properly to show you your flaws. I am not insulting you just showing you the flaws.
Hi, my name is Jack.
I'm an international student studying at UNSW.
I'm earning my Bachelors in Law and Bachelors in Commerce.
I thought my English was not bad, but I went to my tutorial class this morning
my tutor asked me to explain sth (i do not know what sth is) and I didn't expect he would ask me.
I was frustrated out of my mind and speechless!

The rest is not that bad.

So you aren't terrible at speaking English and English is the most difficult language to learn in the world because it consists of multiple languages all meshed together.
Try just listen to the radio and watching tv, listen to how people talk and form their sentences. And maybe read some books. It is clear that you know how to speak English and read it, you just need to improve the skill.

Hello Jack :)

I have a few suggestions. You should watch films in English. Read English books. Talk to people who are English. Your English is good :)

I am Vietnamese and I moved to us permanently 6 years ago when I was 10 and for me idk if I speak it right or not I think its has a bit of Asian accent on some words but whatever haha but he more you talk in English the better you will get trust me just find a friend or a girlfriend and talk a lot ask her/him help you as I talk to my cousin everyday in English and I read game novels

Try voice chat with english persons , don't be depressed you just got nervous that's why you couldn't talk take me for an example I speak arabic as my first language and english as second when I feel nervous I can't speak english or arabic , you have to be self confident

You have to talk to Fluent English speaking people. I mean talk everyday