What do I do?

You will have to ask mummy and daddy to let you have a new one.

Let's see how much more you'll get mad when you see how much a new laptop costs.

Could it be, do YOU think, that YOUR idiocy has caused a hard drive failure?

put it in the repair shop and pay to fix it . after all you broke it .

With no clues what laptop, its model, brand, how long you owned it whether anything in hard disk is important,  a blind guess is that you have a repair shop visit in your future.
Once a guy I knew bought a nice laptop "for parts only" and I fixed it--keyboard flat cable contacts needed polishing, and the hard disk connector was loose.  Still working years later.

I think your hard drive is crashed. You have to discuss it with computer hardware professional. 

You have just learned a valuable lesson in life. Never a good idea to damage a precision device which has many components which have to be correctly connected to each other. If you are lucky you or somebody may be able to  mend it. I trust hat all your data was backed up somewhere.

Yea, you will be lucky to come back on once you replace the HDD. A hard slam could result in the HDD connector getting damaged or even the motherboard cracking. Start by inserting another used HDD in there and see if it is recognized. If it is then just replace the HDD. If not then try the original HDD in another laptop or drive case. If it works elsewhere but not in the original laptop then the motherboard or HDD connected is busted. You'll need a NEW laptop!

now it only has this site "yahoo" on your screen? remove hsrd drive, reset. then replace hard drive and boot to your obvioysly either windoes or mac recovery system and repair hsrd drive.

I had a friend that got upset and tossed their laptop and didn't seem that hard but something messed up. I unscrewed it (some pcs need to be popped open) and checked and turned out inside a wire got disconnected and always easily disconnected since, maybe if you check inside if all wires are connected or not. Maybe broken, if so replace hard drive. I'm not expert. Just going by experience. If you have a geek squad nearby, sometimes they will check for free, just won't replace anything for free.