We can’t make people stay.
Be sad. Cry. Grieve. Wallow in the void that he has left you with and wish he never left in the first place.
It is not wrong to be sad because you’re hurt or to grieve for things that you have lost along the way. It is never wrong to take a step back, take a deep breath, and rest.
I promise you, you will be okay. Things will get better.