Hi Carlie
It is difficult, but if you have no choice, then it is something you have to inevitably deal with. I hated it and dreaded the back-to-work date. We were lucky to find a really good nursery and that helped immensely. We as parents have a great rapport and relaxed attitude with all the staff and this has benefitted our daughter as well. Is it not possible for your little one to attend the nursery you work at? I know some of the girls who work at ours do that, and it's not only cheaper for them but also means they can keep an eye on their little one.
From age 3 months to 2 years we allowed only my parents or my husband's mother to look after our LO, and that was only for 3 - 4 hours if we went out for a meal or theatre, and perhaps only once every couple of months. I always used to worry, and would phone or text to see what was happening while I was away! We co-slept too so I was always with her.
It was only when she reached 2 years old that we allowed her to stay overnight - but only at my parents' house, where I knew they would not do anything I disagreed with and where she would be safe. That's happened a handful of times (she is now 3).
I think you should relax, visit a few childminders etc (or speak to family) and find somewhere you are really comfortable with your child staying whilst you work. And make sure it's okay for you to phone / drop in at any time. This will put you at ease when you return to work. And it will get better - it just takes a while to accept the situation!