Sorry to say that it doesn't necessarily get better. I find how my days go all depend on what kids I have. Certain kids are very stressful. Luckily my group now is great although I prefer the days my part-time kids are away as they are a bit more demanding. Maybe be more strict with the kids. If you set a good standard of rules there won't be as many kids hurt or tantrums. I don't allow tantrums and the kids learn very quickly what is acceptable. No hitting, no throwing toys, no running in the house, no jumping on furniture, you must all stand in line and wait until I tell you that you can go up the stairs etc - it all helps keep order. Also if there is crying for no reason then they must sit in timeout until they are finished.
All kids need to nap. My daughter who is soon 4 doesn't so she sits quietly upstairs and watches TV. She knows if she makes noise that TV will be off and she will be put for a nap. I have another 4 year old that lays in her bed and looks at books the whole nap time (sometimes sleeps). All other kids sleep. If they wake during nap I will see how long it has been and if it has been over 1.5 hours I will go get whoever has woken up and they get to sit on the couch with me and look at books. I do this because I don't want the little ones making too much noise to wake everyone else.