Breastfeeding tips

Any tips for transitioning a new born from solely breast latching to a bottle?? My 3 week old will not take a bottle or a pacifier I feed on demand but his demand seems to be all day or at least every 90 minutes the last few days have a mental struggle for me and I fear it may be making my ppd worst. I have 2 older toddlers who also need me and it’s hard to balance his feeding schedule while also having to tend to my oldest. All advice is appreciated! Thank you in advance