My kid is a patient at the ACH as well, currently visiting once per week with a serious but manageable condition (his blood doesn't clot properly). Nothing but great things to say about the ACH. We also have other family members who are quite ill, so at the very least, it is comforting to know that your child is in great hands as you learn more about managing their condition so you can focus on the other things.
An iPad with cartoons is an excellent way to distract them as you prepare to give your kid a needle