Help mamas!!!

Hi mamas❤ so I'm due in 5 weeks and I'm thinking about not breastfeeding because my kids are very close in age. 4,3,2 and 10 months so I imagine it would be difficult to take care of all my children while trying to feed the baby. Also I've never been successful with breastfeeding for long.. I've read books, met with lactation consultants where they physically help me but I still always end up pumping the whole time. Lets admit isn't fun but that's the only way I could get it done..

Formula sounds easier to be able to take care of all my children. My question is about formula fed children. I breastfed all my children as long as I could but for my third child she only lasted 2 weeks and she is the small one in the bunch. Could it be because she was formula fed right from the start?