Laptop wont turn on.

Hello,
So, during class, i was on my laptop when a friend was asking if she could charge her cellular phone using my laptop, so i agreed, but when i looked at what she charged, it turned out to be a powerbank. Before i thought of pulling it out, i left the room to go talk to someone over the phone, with my laptop still powering her drained powerbank, and when i came back, my laptop just wont open anymore, even if i charged it, no light (green, orange) opened. What could possibly be the problem? Im panicking. Exam starts tomorrow and all of my files are inside.