I am living in fear in my relationship.

I need somewhere to vent. My boyfriend is a recovering addict. He recently relapsed few months ago. Anyways, two weeks ago, he was taken to the hospital since he overdosed. Basically a suicide attempt. Getting a call from the hospital at 4am letting me know about my boyfriend was one of the scariest experiences in my life. He suffers from depression which led him to addiction. He wants to get better and is trying his best but theres days where he goes mentally crazy, tells me how much he wants to kill himself etc etc. I can’t sleep at night anymore. I have constant dreams of my boyfriend overdosing and dying. I live in fear that one day i am going to get a call that my boyfriend took his life. I can’t stand it anymore. I love him so much. Theres times where i want to leave the relationship since this is all affecting me so much. But i am emotionally stuck. I also feel like if i leave, it will make his depression worse and make it seem like i gave up on him. Nothing i can do can make anything better. I would give anything for him not to go through this. I don’t know what to do or how to deal with this. I get anxiety attacks and heart starts pounding every time his dad text/calls me. I love my boyfriend so much but i can’t live like this anymore....