Gomez99
Please for the love of god do it as soon as possible

Agreed!  I am a little concerned about the lack of motivation in doing this properly.  The power supply absolutely needs a proper ground reference point to work properly.  With an improperly grounded ("floating ground") input into the power supply, the power supply will do the best it can, but the difference between the PSU's floating ground and the case's ground can cause major problems and cause your power supply to fail or even cause your computer hardware to burn out in worst case situations.
 
Your PSU uses pulse width modulation ("PWM") to regulate voltage output.  It's voltage output is referenced in relation to "ground" potential voltage.  If the ground is "floating" (not grounded), any static electricity which builds up in the PSU's ground wire will offset true ground and cause a similar voltage rise in PSU output.  As you have already experienced by the fact that your computer case zapped you and your headset popped, your PSU is not grounded.  Grounding your case is a band-aid but does not fix the root problem.
 
You have grounded the PSU's output by grounding your computer case.  More than likely, the grounded output is tied into the ground input which means that when you grounded the case, you probably also effectively grounded the PSU's input; but it is not certain and is a risk you are taking by assumption.  If you want to be sure that you did it properly and want to make sure you don't burn your PSU out or burn out the computer hardware in your case, you need to ground the PSU input.  No normal computer case in the planet is grounded directly in the way you have.  Everyone grounds the input wire into the PSU and you should do the same in order to use your computer the way it was designed to be used.