I don't know what to do

My first son was stillborn and with my rainbow I had to take my maternity leave as soon as possible due to complications and I now have to decide what to do job wise. I am full time and want to go back at least part time, but all I can think of is my rainbow. I can't leave him I fear something will happen and I don't trust people to have him, I just think back to seeing my sons coffin and picturing this time it'll be my rainbow in the coffin.

I have no idea what to do when he goes to his nan and grandads for the night I'm just full of anxiety even though his nan is a nurse so he's in safe hands. I just keep picturing terrible stuff happening, like I'll wake up and he's gone. When he's asleep I hardly sleep as I'm always waking to make sure he's still breathing, even during the day and he's having a nap I have to make sure he's breathing. I also find myself full of anxiety when I'm in the car or on the bus with him or even out thinking something bad will happen to him.

I don't know how I will go back to work or if it's worth going to the doctors. I've already had depression, agoraphobia, anxiety, ptsd