B.S.
I've been a child care provider for over 20 years (http://www.missbrenda.com). The mothers who bring breast milk have found a system that works well for her, me, and the baby. If you are consistent, you'll find your milk supply will increase over time. It's a lot of work at first, until you get into a good routine.
They make sure to pump any milk that the baby leaves each feeding. Then, while at work they try to find time to pump two or three times through the day. Now, in most cases, that gives us two full feedings during the day while she is at work. Then, I supplement with a formula for the third feeding.
Now, most any formula is nutricious...just compare the labels. You probably should have offered the baby some formula from a bottle a few times over the past few weeks, but it will all work out. Most use Enfamil Lipil w/iron. But, if you compare the labels you'll find that most brands have the same ingredients...even the cheaper ones. Some formulas are easier to mix than others. And, you'll have to adjust if the baby begins to spit it back up...but that comes with time and a good provider will help you and be knowledgeable in that area.
So, at the end of each workday the mom brings me the milk she has pumped that day either in bags or in bottles. I refrigerate it and have it ready to start on the first thing the next morning. It's really very simple.
Adjusting to separation is usually easier on the baby than the mom. The baby will be fine. A good provider will hold and cuddle the baby and get it into a good routine for you. I usually email my new moms at work with a mid-morning and mid-afternoon update on how the baby has done, although, I welcome their calls if they prefer it that way. It's just that I usually have time during the morning and afternoon naps to contact them instead.
Good luck, God bless and happy pumping...
Ms B.