Supplementing w/Breastmilk?

Amanda • Endometriosis fighter. Mommy of a 5yr old daughter and baby #2 due mid August!
So it's always been either strictly formula, breastfeeding & supplementing w/formula, or just breastfeeding. But has or will anyone mainly use formula and occasionally breastmilk
With my daughter I tried so hard to breastfeed/pump but couldn't keep up with her or make a stockpile for when I went back to work. So I snuck her formula and felt guilty! Emotionally I couldn't handle it. This time I was thinking about manually pumping a couple times a day, but using formula the rest of the time. Anyone else?