Are there any other moms who aren't the default parent?

I'm 25 FTM and have been back at work full time for about 4 months now. My partner is the stay at home parent and takes care of our son who is 8m.

Even after we left the hospital my partner was on top of it, cleaning bottles, waking up for feedings, putting him to bed. After my recovery period I tried to help more but would find myself getting overwhelmed quickly. My partner was the oldest and raised all of his brothers. I'm the youngest in my family and while I have experience with babies I'm not as good as him.

I've been trying to be better about being 50-50 with childcare (rn it's 60-40) but with me at work it makes sense that my partner knows how to handle him better. It's also sometimes hard to speak to other new moms, a lot of the issues they have are with being a stay at home parent and I don't have the same experiences.

I feel guilty for not being the primary parent. I come from a culture where the mother is expected to stay at home with the baby so I almost feel like I'm failing as a mother. Anyone else have an opposite situation?