Disappointed with myself...

Have been feeling really down these few days... have been questioning myself if im smart enough for uni? am i turning dumb? i have reached a stage where no matter how much effort i put in i wont get any results... i totally dont understand anything the lecturer teach nor anything my friend is saying... i will read the textbook until i get so frustrated i started crying, in fact i have nvr pass one day without crying... what am i to do?

A v emo jia