I too am sorry that you are going through this. I understand completely, my 3 children are grown now, but when they left home I was devastated. I felt I had lost my prime role and identity in life. However, their moving on allowed me to move on. I went back to school and got my nursing license. I achieved a long held dream with them cheering me on.
I now have 3 grandchildren who are the loves of my life. and they too are growing quickly. But the love has multiplied for all of them. It is sometimes agonizing to watch them make mistakes, and sometimes I have to keep my mouth shut, which isn't easy. But I cherish each moment and love each stage of their lives. I nope this helps you as you deal with these feelings. I cry as I write this for you and knowing how painful the journey is. Hang in there. it's worth the ride.