Laptop is running extremely loud and slow

You computer has an issue with a temperature sensor malfunction - when your computer can't read acceptable data from a temperature sensor, it revs the fans up, and executes a process that takes over the processing power in order to prevent the computer from being exerted, to prevent it from heating up as a safety mechanism. If you open up Activity Monitor, there will likely be a process called "kernel_task" that is taking up all of the processing power. There is a possibility that the drop dislodged a cable, which carries temperature information from another component within your computer. I would open the mac up and check to see if any cables are not connected properly.