Settling... Not

My baby is 3 weeks and 2 days old today and refuses to sleep in her crib. Or sleep pod. Or swing. Pretty much anywhere but our arms/chest or co-sleeping in bed (where she does the sleeping while I'm wired staring at her making sure she's ok). We're struggling to get her to settle at all. The second she doses off and we put her down she wakes up. Tried white noise, swaddle, dark room, giving the bed a slight angle just in case it's reflux, everything. I'm also trying to primarily breastfeed but she has a bottle of formula during the day and one at night. She doesn't nap during the day either. She gets around 10 hrs of sleep a day including all sleep day and night. I don't believe in letting her 'cry it out' and I like to respond to her cry immediately. Partner thinks I should just let her settle herself.

A separate concern, she's struggling to settle on the breast sometimes and bops her head like crazy and cries when the milk is not coming out fast enough for her. I'm still not sure if she's getting enough. Can baby's stomach be stretched out? There are so many controversial articles it's unreal.

Any suggestions please and thank you