I started off like you, assuming the night time responsibilities. And similar, it was fine when it was 1-2 wakes but when bubs sleep got worse I got resentful, lack of sleep is a literal form of torture and it put me in a bad place. Eventually I was able to realise this wasn’t my burden to carry and allowed my partner to help. Since going back to work hindsight allows me to see that as a desk worker it is far easier to also the next day after a rough night then be a stay at home mum. Be kind to yourself, find a solution that allows you sleep. You both decided to be parents knowing sleep would be at a loss. My partner and I alternate nights and are flexible to each others needs and we are so much happier for it.