Quetiapine

My psychiatrist decided that I should start taking 25mg of quetiapine at night to help me sleep and maybe stop my nightmares.
I started taking it a week ago and it is a bloody nightmare. I get off to sleep really quickly but am waking up about 4am in an absolute mess. I just can't get myself out of the nightmare. Images stay with me and everything is so bright and vivid. I just can't ground myself and am disassociating.
I stabbed myself badly in the stomach and ended up at A&E where I had to have a CT scan and be stitched up.
During the day I don't feel safe. My head is all over the place. Thoughts of hanging myself are never far away and I'm not eating or looking after myself at all.
I have rang my MHT, the crisis team and seen my GP but they are not listening to how frightened I am and how unsafe I feel.
What do I have to do to get some help?
In reality I know there isn't much they can do. I don't want to be locked up. I need to stay at work but I'm struggling and feeling alone with it all.
Should I stop taking the quetiapine? Should I try to ride it out with hopes it will improve? I just don't know what to do.
I do know that right now I just want to curl up and die.