So depressed

I am so so depressed that I have recently got a bad assessment for my English pronunciation. Did I do so badly? Or is it related to that I spoke out "Did the teacher say /da:ta/ for data? ". Oh, that was a bad joke...even though she actually did.

I should say that I really am unmotivated when I was said something bad about my English but they don't give any correction or advises. In this case, I wouldn't know how improve it forever!