Self government and homeschool high school

I have a 14 year old freshman son who is currently completing 5 classes in our homeschool curriculum. He has Biology, Omnibus 3, Logic 1, Math, Language Arts. He is current in his 2 classes he takes with a co-op and online but behind in his other 3 classes. He blames my husband and I for being behind. I am fine taking things slower and doing less, but if he takes only 2 classes a year then it will take 10 years for him to finish high school! How can I help him to take ownership of his time and schedule? How can I help him with self government of his subjects? Right now he gets angry and starts immediately deep breathing at the mere mention of being behind. I give him 3-4 hours of school a day to complete and that includes his online classes. He has karate (2xs week), drums, gliding (planes), and church youth group and volunteering outside of school. He has a check list and even his own notebook for “to-do lists”. He wants to fly commercial jets as a career. He gets As and Bs when he does the work. Please help me teach him self government and to stop blaming others, etc for being behind. I feel so lost at how to motivate him.