My first thought is do you want to continue to breastfeed? If so, ditch the bottles, ditch the formula and nurse her on demand 24/7.
Second thought-at barely a month old why do you think she has never taken a lot from the breast? Because she was nursing fairly often? Because she was nursing quickly? These are all perfectly normal. It's normal for a new a baby to nurse every 1.5-3 hours. And you time from when you start not when you finish. So if you have a little one that is on the 1.5 hour schedule it can seem like they are nursing constantly and could cause one to doubt that baby is getting enough when baby is doing just fine and acting perfectly within normal limits.
More fussy? Yep could certainly be the formula. It is much harder for baby to digest so that's why a formula fed baby will go longer between feedings. A breastfed baby is getting the very easily digestible breastmilk and it moves thru the system with greater ease and less tummy distress to baby.
Right now (the first 6-8 weeks) engorgement is normal as baby is trying to regulate your supply. They will nurse all over the place sometimes. Sometimes they are very actively nursing and other times not so much because baby is giving your body signals on how much to produce. By about the 6-8 week mark your baby has got your body making just what they need. By adding formula you are throwing a wrench in that system.
If you pump after she eats you are telling your body to keep making more.
If you want to nurse your baby drop the bottles and drop the formula. As long as she has wet diapers (breastfed babies can go days without a bm so worry less about poo) and she seems satisfied after she's getting what she needs. By putting baby to breast often you give her the chance to do things the way nature intended and she becomes better at nursing.