This is called Obstructive Sleep Apnea(OSA)
In this picture above you can see that there are two different types of scenarios. On the left the tongue and muscles are forward positioned and the airway is open. This lets you get air into your lungs like you would need. But on the right, the tongue and muscles collapse and close off the air passage. This causes Obstructive Sleep Apnea, or in other words- you snore and are gasping for air the whole night and wake up exhausted like you just ran a marathon!