I just feel that you shouldn't worry too much.
Also, worrying too much will just make you fall sick easily, then won't that be even worse?
I sent my #1 to infant care at 8 months because I was starting a new full time then. The school was new then, and there was only 1 teacher and 1 infant!
I was a first time parent, I was jittery too.. I was just like you but, first day of school, I told #1 to play and be curious, be observant.. and then i went to work and the worrisome thoughts were washed off my head.
Since it was LO's first time under other people's care, I tried to pick her up early.. and overtime, I learnt from other non-infant teachers that she was such a joy among the babies and the older kids in school.
So, don't worry and give day 1... 2.. 3.. and on a go.
Most importantly, don't go feeling that you are not good enough as a mother because you had to put LO there. What you are doing for them now, even just a little bit, are also for them.