How can I make this intro better?

Change 'then' to 'than' in the 9th line. The "I really should have gotten a better sleep for my calculus exam" kind of interrupts the suspence of finding out what happened to her mother. That's my opinion, though. Also, are you describing the table as a 'cracked island'? Maybe try something else in place of that, like 'cracked oak'. Or whatever you want to do. The part when the mom goes into the house and making loud noice in the kitchen, where it says: "this whole situation has erupted into something much more serious than I would have ever imagined", I didn't understand what you meant. I thought at first that it was an fight between both parents. Maybe you could say 'my mother's drinking problem' to make it more clear. I hope this helps!