PC Slows Down while multi-tasking even after having all proper resources.

I have Dell Vostro 3478. 

My Laptop Configuration:

   OS:  

      Edition: Windows 10 Home Single Language
      Version: 20H2
      Installed on: ‎11/‎1/‎2020 
      OS build: 19042.685

  Resources:

    Installed RAM: 12.0 GB (8+4) ,Hybrid
    System type:  64-bit operating system, x64-based processor

As you can see, I have minimum requirements for minimum multi-tasking

Problem:

  Whenever, I do multi-tasking like Playing Songs in Background Via Microsoft Edge and working with PyCharm.

  My pc gets super slow  with Buzz sound like I couldn't do anything other then moving mouse.

  The Frequency of Problem is directly proportional (Related)  to the time I spend on my laptop.

  Sometimes I need to Force Shutdown my PC. 

  Its the same while playing games.  

  The Problem is not with a particular App, It is same thing for all Apps. 

I've Reset my pc but, its still the same.

This Problem intolerable.

Please provide a Solution for this problem.

                                                                                                                                                              Thank You.