How were you when your son started? Did you feel similarly but you all adjusted and got used to the same routine? If so it’s likely to be the same this time.
Being a bit devil’s advocate but if you’re concerned she won’t be happy in a nursery setting and particularly worried about bugs, then does it have to be a nursery? My DD went to a childminder and I was so much happier with that, it just felt right for her ti be in a home setting with one very lovely adult who she formed a close bond with. They get mixed reviews on here but honestly our childminder was amazing, if you can find the right one I think they are a great option for babies/ younger children.
I think she came home once because she’d been sick, was fine by the time I got her home. There were no other bugs despite childminder obviously having other children in the setting and taking them to various playgroups etc. So it’s not a given they’ll get ill a lot although I appreciate we were very lucky and it’s more common for them to pick stuff up. Another advantage of the childminder was that she was pretty sensible at not trying to send her home at the drop of a hat.
There’s advantages to nursery too obviously, and presumably you like the one you picked - have faith in your judgement and in their ability to do their job. I was convinced my DD would NEVER nap anywhere but on me, with a lot of work to get her there, and we never actually did manage that at home. But the childminder had her sleeping in a cot by the first nap time, and friends whose children went to nursery said the same about how they have some kind of extra powers that we parents don’t seem to posses!
You’ll still have more time at home with her than you’re away, and you will get to have a hot cup of tea in peace and go to the toilet unaccompanied and all that stuff (depending on the job I guess!). Her non nursery days will be really special - I kept Fridays off with DD right the way into Reception (until it was clear she’d rather be in school with her friends) and our ‘mummy days’ are still a special memory and I miss them.