Moms with 2 that had a hard time with 1, how do you do it?

I’ve always envisioned myself having many kids, but I have a 4 month old and I have a hard time just taking care of her while keeping up the house. Some days I want to lay in bed all day with her because I’m so exhausted while others I’m able to get a lot done and feel like super mom.

If you had a hard time with 1 child, how did you manage more?