Don't feel bad if you cannot afford a 2nd glider right away or if your current glider does not accept a new friend.
Gliders will not self mutilate being alone, that is a myth.
When you have a single glider you need to add toys that challenge them. Like forging toys that challenge them to find treats and food. Ball pits are another toy that gliders love to play in and keep them busy for hours if you drop treats like meal worms in it. Artificial vines hung at different levels in the cage with treat cups hid in them are great forging. There are many vendors out there that sell toys like these. And many are very easily made at home. When you can't spend a lot of time with a single glider as long as you can keep them busy and keep them in a high traffic room in the house they can thrive.
Don't get me wrong it is best to have a cage mate for them to help pass time and we are poor substitutes for another glider to play and cuddle with. But it is not a death sentence for the glider.