I feel lost

I just started uni its my first year. At the beginning i was enjoying my classes then some girl accused me of something i didn't do. She ended up talking about me. to everyone in my class. Now i feel demotivated and im not doing well at all in my modules. I fear i might fail and i don't know what to do. I've been thinking of stopping but then i think of my parents who invested much money as its a payable uni. Can someone hwlp me i dno't know what i should be doing