Difficult Time Working Nights

I recently moved to VA from out of state. I have been in L&D/OB my entire nursing career,( 10 yrs).

When I got here I found that L&D jobs are limited (esp. on days).

My history- I have a strong history of depression and ADD, has had it's ups and downs over the years-but have not had problems that interfere with my work. I do take medication to manage both.

The job I was very recently hired into is night shift PRN, I have worked nights before, when I first graduated, so I thought I could give it a try for a while to see how it goes until they let me start picking up day shifts.

After 2 weeks of hospital orientation, I started my unit orientation on days, had 5 shifts, did OK.

So, I thought I could do it, my last 2 shifts of orientation were on nights. It sent my med schedule and depression into a downward spiral much quicker then I would have ever expected. It took me over 1 week to feel normal, (actually get up out of bed) with a visit to my Psychiatrist. He agrees that nights are not a good idea for me at this time.

I know I need to notify them ASAP, but I am embarrassed about this. I would like to stay and work PRN, but I know I cannot keep the schedule on nights. I don't know how to go about this. Should I tell them about WHY I cannot work nights and have that "stigma"? Do they really need to know my medical hx? Should I just resign and tell them this is not working out for me?

I am in that 90 day new hire probation. I don't want to let them down, but cannot put myself or children through it. I thought I could do it, I would not have taken the job had I known it would make me feel so bad. I am just asking for some advice on how to handle this. Thanks so much!