When i was moving my metal stand it hit the side of my 75 gal tank chipping a corner. you can't see it through the tank from the inside of tank....and some little glass bits fell off.....but its not big and is more of a chip than anything.....do i have to throw my tank away...

Any place where there is a significant amount of structural silicone on show is an accident waiting to happen. Anywhere where the chip is longer than the glass thickness is an acident waiting to happen. Don't risk it, get it fixed, or keep it somewhere where the mess is easy to clean up
It would be an instant failure in a large tank due to the volume of water and pressure involved...