Communication is the only solution. I suggest a marriage counselor that helps you learn to dialogue. Google some in your area, and search for 'reviews' on them. That's how I've found my doctors, by looking for other people's reviews, and picking those who have the best reviews.

You have to be able to speak until you reach a conclusion you are both happy with.

The other thing you need to do, IMO, is have stronger boundaries. For instance, tell H that if you are taking his son to practice 4 times a week, you would like to know what he is going to do to make up for the time you're expending on his son's needs. Don't let him just brush it off, or get mad at you. Make "I" statements, not "you" statements (I feel like I'm being used in this family, while I don't see anyone else putting in any effort. Why is that?)