Hello , how do I fix this?

I have my finals coming and this happens lmfao What do I do? it just randomly came off hello?!?!? So basically 3 yaar ago my younger brother who was 11 threw it on the ground ..at that time there were small cracks which I did fix but today randomly this happens My family is NOT rich to afford another one! This was expensive enough already .. what do I do 😭😭 I am like a teenager so I'm clueless if I should call customer service or not.