Lost my adult (18yr) son a month ago. I think I'm dying too.

On September 29,2019. My 18 yr old son was in a fatal car accident. It happened minutes away from our home.
I don't feel strong enough to make it through this. His birthday is coming at me very quickly its Nov 30. I dread every second that I'm alive. I definitely feel like I can make it through years of this pain. I see other parents that have lost children (my own mother included) and wonder, how do they keep moving forward? I know it's not because they love their child less than I love mine, I feel they must have strength that I don't have.... that I can't find.
I'm still trying to figure out how I got from him leaving that morning and saying "I'll be right back." to .... this... me sitting here, telling everyone that my baby has gone to the other side and that I want to be with him.