If you are only relying on pumping... your breastmilk production/supply can lessen, over time. There is nothing like direct nursing, to keep up with the supply/demand of a baby. Maybe, the recent pumping, has affected your supply. Although with your schedule, I know it can't be avoided.
Or, ask a Lactation Consultant, on how best to trouble shoot it. As each woman is different.
try to direct nurse whenever you can.
She is waking now a lot at night, because she is going through a "growth-spurt." She is waking because she needs more intake, to keep up with her growing demands of intake... as as a child grows, they naturally need more intake.
Per my Pediatrician, for the 1st year of life, Breastmilk/Formula is the PRIMARY source of nutrition for a baby... NOT solids, and NOT other liquids. AND, a baby must be fed on demand for the 1st year. At this age and point, "solids" is just an introduction and 'supplement' to breastmilk/Formula. Not to be relied on TOTALLY for "all" a baby's intake daily.
Perhaps, try another kind of bottle. Versus just switching Formulas too much. For my son, he LOVED the "MAM" brand bottles, which you can get from www.amazon.com It is great and I love this brand. AND it is "BPA" free.
Next, HOW is she being given the bottle? And WHO is giving it to her? Is she propped up at feedings or held in the lap/arms, or on a Boppy pillow? For some babies, this can make all the difference.
Also, make sure she is burped during the feedings... maybe she is getting 'gas' which makes them seem full.
You said she has been only breastfed up until this point... and then per her waking up every 2-3 hours to feed during the night, you can't pump. So excuse me for being 'dense'... so how is she being fed at her night wakings? Can you just nurse her directly instead? If you nurse directly MORE OFTEN... then the logic is that the body will produce more milk, per demand.
Often times too, a baby will often "cluster feed"... meaning they even will 'need' to feed even every single hour... otherwise they will always be hungry. This reflects their growth-spurts and need for more intake. If not getting it, then yes, they will wake more, due to hunger. As you said.
Perhaps, I would really seek a Lactation Consultant for advice... on HOW you can INCREASE your output. And, keep hydrated and drink LOTS of water, which is supposed to help.
She is probably 'rejecting' the Formula/bottle, because you are there and she knows that. And when you are not home... some babies will actually NOT take a bottle... in anticipation of waiting for their Mom. But as you know, then they may not be getting enough intake.. and this can affect your milk output.
I think, (1) try to troubleshoot how you can increase your supply... then nurse directly whenever you can... no matter how often, so that she gets enough intake and hopefully therefore making your breasts produce more milk. (2) And use pumping/Formula ONLY if you have to... and (3) try using a different bottle/nipple.
Then, ask your Pediatrician about a "plan B" in case your milk supply diminishes more... and then you will have to, supplement her with Formula... but if she does not take that.. then ask the Pediatrician for what alternatives you have. Because no matter what, she has to be getting enough intake from either breastmilk or Formula.
Ask your Pediatrician RIGHT AWAY on what you can give her... since you are working all weekend and it can't be avoided.
Some babies, have to be fed with a medicine dropper sometimes if they are not taking the bottle, for example. My friend had to do that, because her baby was not a good latcher nor feeder.
All the best,
sorry I don't have a magic solution,
Susan