I’m scared to death

I had nightmares all week that my boyfriend had committed, for lack of better words. This morning he says his depression is coming back and coming back full force. I’m so scared of losing him, I’m trying everything, I’m distracting him and talking him through it and I don’t know what else to do, I’m being extra sweet to him and reminding him how loved and appreciated he is. I’m just so scared and I know he is too, I wish I could make it go away