Trying to build milk supply

You need to eat more since making milk uses energy you need to increase calories healthy ones. Fenugreek and milk thistle are also good supplements that naturally support milk production. There are so many products out now just research a few. Good luck!!!

Don't pump lovely if u want to build a milk supply after a formula. It won't be anywhere as affective as breastfeeding. Baby's lips have to make contact with your nipples in other for your body to receive the message it needs to be making more milk. Exactly as you said, pumping atm will be very hard. The more you latch your baby, the more milk you will have. I stopped feeding when my daughter was 21 months and now 3 months later I still leak so I am positive if I let her go on the boob I would have more milk again, but I wanted to stop X
If for some reason u can't, don't want to breastfeed but only pump it will be harder, but unfortunately I don't have any experience with that so can't advise, but worth contacting your midwife or local nursing support, they could have resources about pumping too.

Hydrate, Hydrate, Hydrate: water, coconut water, smoothies, and Body Armor drink, paired with meals and snacks throughout the day, as well as pumping or feeding the little one every 2 to 3 hours consistently, so your body knows it needs to produce more milk for baby. Breastfeeding is a lot, but you got this, mama.