We installed heavy glass artwork on drywall it is 16x5 feet , is it secured or not !!?

Question:we drilled holes in the glass and we were supposed to use stand offs but it did not work ,the wall was not strong enough to hold the glass.Then we decided to use fasteners and clear sillicon to secure it. It seems stable for now but is there any thing else we could have done to insure the glass would not move

Answers:
oh dear ? locate the studs behind the sheet rock,with a stud finder , screw some blocks to the stud ,aka stand off, i guess, use a 3in screws, if you dont you may not have glass. just a pile of glass