So frustrated😩

So I'm starting to get really frustrated with my husband. We have two kids (2 and 4 months). We've been together for 5 years and married almost 3. Our relationship is awesome apart from this one thing. He works from Tuesday to Saturday (office job) and only has to work until 3pm on Saturdays. His new thing is to come home on Saturdays on take a 5 hour nap, he gets back up around 830pm then goes back to bed around 1030pn for the night. It's so frustrating because my two year old adores him and wishes he was around more. Not only does he take long naps on Saturdays though he usually does it everyday of the weekend and then sometimes just goes to bed at 6pm (he gets off work at 5) on week days too. How much sleep does one person honestly need? I have never asked him to get up at night with either of our children because he worked and I'm a SAHM but something has gotta give. I've told him how I feel about it and he always claims he's going to stop but never does. We're best friends and I love him to death I just have no idea how to handle this situation. He so badly wanted this family and now I feel like I'm taking care of the kids alone 90% of the time since we moved out of state away from our family and friends when our youngest was born so I feel very alone. What should I do?