Combination feeding?

Tr

I had my baby 6 days ago (I think?). I have been doing combo of bottle and breastfeeding. Initially because I needed to supplement with formula to get her weight up as she was preemie, but now I am able to exclusively give breastmilk (I make 2-3x as much as she can eat at each session). I have been doing combo with the bottle still for my own mental health, as well as to give dad time to feed her because he has mentioned how much it has helped him bond to her, but I keep hearing how I should be doing breast only and that's what I need to do to have my supply be successful (doesn't seem to be the case though?). All the l&d nurses, the lactation consultant, the peditrician... but I also have to go back to work in a few months, so I'll have to do this eventually anyways.

With everybody pushing, it doesn't seem like a choice anymore, and I feel like I'm doing it all wrong. I still breastfeed her most of the time, she just gets pumped milk a few times a night so I can get some sleep too, or if she wants to cluster feed too soon after I've pumped.

I thought that she was still getting so much benefit from being exclusively breast milk (the formula was hard on her tummy) and being mostly nursed that she was fine, but I feel like I'm failing her now since everyone keeps telling me differently. Isn't it still better than if she had to do just formula? She's our first and I just need some support on this because I'm confused.