Visitor Visa - B2

I am an Egyptian citizen and a student at the faculty of Engineering Alexandria University Civil department 21 YO
I applied for a B2 visa when I got refused I was so much worried maybe that's why
I am travelling for a friend
VO : good morning
Me : good morning sir
VO : you are a student??
me :yes sir
- what collage
- answered have papers from the collage want to see em??
-no ,why are visiting US
- a Holiday and to my friend YYYY I have papers from him , you want to see them??
- no ,for how long he have been there
- three years sir
- what visa did he got "tricky one"
- tourism visa "I answered wrong he got it F1"
- sorry you aren't getting the visa today
your ties to egypt are not strong enough

now My question is
should I apply again??
specially when you know that I have a computer shop here in Egypt but I didn't mention it to him
also should I change the occuopation to "shop owner instead of a student"??
please respond mentioning what was wrong in my answers
thank you in advance