Can't cope

My partner had emergency surgery back in November on his bowels and a large mass was removed.

He's been treated for bowel cancer, but due to various issues only just started his chemo on Monday. Its now 4:40am Friday morning, and I'm sat with him in A&E, been here for 6hours.

They think he's got an infection. I have no idea what's going on. I feel like I can't do this. I want to run away, and leave. I can't cope with him being in this state. I'm exhausted, and have fibromyalgia and mental health problems.

How am I supposed to deal with this?