For bf or bottles I always use a boppy/or travel boppy. I have terrible posture and when I don’t use it I am soo hunched over and regret it lol
Speak to your infant feeding team for help. They will come home and guide you
I BF but I leaned on my bed head (which is fabric) had a pillow behind me and a V pillow in front holding the baby up.
I prop with pillows, oh and keep a V pillow on the sofa!
Get a breastfeeding pillow was a lifesaver for me in the beginning
I prop up my forearm with pillows and put one under baby too.a couple behind myself or a comfy chair helps too. Sometimes just position baby in my lap while I'm crisscross applesauce and that helps too