Firstly, congrats on your baby girl

I had a simialar time at 3 wks and found feeding every hour or so such a drain. THe advice I got from my MCHN was that feeding him so regularly he was getting a lot of foremilk, and not getting the hind milk (fat) to settle. I ended up expressing for a day to get both fore/hind milks and giving it to him in a bottle, he had 2 or 3 of these EBM feeds and we got it right again. Too much foremilk can give them wind = unsettled = crying = overtired = unhappy mum!

Just a suggestion from my own experiences recently.

Also, wehn you feed her, offer the same breast for a 2 - 2.5 hour period so eventually she drains that breast and then offer the other one.

If wind, try propping her up to sleep during the day - raising mattress of the sleeper bed with a rolled towel underneath it to help in digestion. Warm baths - try getting a big bucket - nappy one if you have one are much bigger - or laundry sink etc and put bubs in the water vertically instead of horizontally - she will bring her legs up naturally and might push some wind out with the nice warm water on her belly - hard on our arms, but worth it.

Hope some of that helps and good luck !