feeling suicidal

I have suffered with severe depression and anxiety all my life on and off.
Today is bad, I'm 31 weeks and I just feel like life is pointless. I feel so deeply sad, I feel like I have no hope. I don't know what to do, I wouldn't do anything to harm my baby but the thoughts are still there. I'm under a mental health service and on medication yet I still feel this unbearable sorrow. I just hope this feeling lifts soon.